美国EPA标准方法

DETERMINATION OF ETHYLENE THIOUREA (ETU) IN WATER USING GAS CHROMATOGRAPHY WITH A NITROGEN-PHOSPHORUS DETECTOR

Revision 1.0

December 1992

D.J. Munch and R.L. Graves

T.M. Engel and S.T. Champagne

Battelle, Columbus Division

ENVIRONMENTAL MONITORING SYSTEMS LABORATORY

OFFICE OF RESEARCH AND DEVELOPMENT

U.S. ENVIRONMENTAL PROTECTION AGENCY

CINCINNATI, OHIO 45268

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DETERMINATION OF ETHYLENE THIOUREA (ETU) IN WATER USING GAS CHROMATOGRAPHY WITH A NITROGEN-PHOSPHORUS DETECTOR

1.0SCOPE AND APPLICATION

1.1This method utilizes gas chromatography (GC) to determine ethylene thiourea

(ETU, Chemical Abstracts Registry No. 96-45-7) in water.

1.2This method has been validated in a single laboratory during development.

1 The method detection limit (MDL) has been determined in reagent water and

is listed in Table 2. Method detection limits may vary among laboratories,

depending upon the analytical instrumentation used and the experience of the

analyst. In addition to the work done during the development of this method

and its use in the National Pesticide Survey, an interlaboratory method

validation study of this method has been conducted.

1.3This method is restricted to use by or under the supervision of analysts

experienced in the use of GC and in the interpretation of gas chromatograms.

Each analyst must demonstrate the ability to generate acceptable results with

this method using the procedure described in Section 9.3.

1.4When a tentative identification of ETU is made using the recommended

primary GC column (Section 6.7.1), it must be confirmed by at least one

additional qualitative technique. This technique may be the use of the

confirmation GC column (Section 6.7.2) with the nitrogen-phosphorus detector

or analysis using a gas chromatograph/mass spectrometer (GC/MS).

2.0SUMMARY OF METHOD

2.1The ionic strength and pH of a measured 50 mL aliquot of sample are adjusted

by addition of ammonium chloride and potassium fluoride. The sample is

poured onto an Extrelut column. ETU is eluted from the column in 400 mL of

methylene chloride. A free radical scavenger is then added in excess to the

eluate. The methylene chloride eluant is concentrated to a volume of 5 mL

after solvent substitution with ethyl acetate. Gas chromatographic conditions

are described which permit the separation and measurement of ETU with a

nitrogen-phosphorus detector (NPD).

3.0DEFINITIONS

3.1Artificial Ground Water -- An aqueous matrix designed to mimic a real ground

water sample. The artificial ground water should be reproducible for use by

others.

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3.2Calibration Standard (CAL) -- A solution prepared from the primary dilution

standard solution or stock standard solutions and the internal standards and

surrogate analytes. The CAL solutions are used to calibrate the instrument

response with respect to analyte concentration.

3.3Method Detection Limit (MDL) -- The minimum concentration of an analyte

that can be identified, measured, and reported with 99% confidence that the

analyte concentration is greater than zero.

3.4Internal Standard (IS) -- A pure analyte(s) added to a sample, extract, or

standard solution in known amount(s) and used to measure the relative

responses of other method analytes and surrogates that are components of the same sample or solution. The internal standard must be an analyte that is not

a sample component.

3.5Field Duplicates (FD1 and FD2) -- Two separate samples collected at the same

time and place under identical circumstances and treated exactly the same

throughout field and laboratory procedures. Analyses of FD1 and FD2 give a

measure of the precision associated with sample collection, preservation and

storage, as well as with laboratory procedures.

3.6Instrument Performance Check Solution (IPC) -- A solution of one or more

method analytes, surrogates, internal standards, or other test substances used

to evaluate the performance of the instrument system with respect to a defined set of criteria.

3.7Laboratory Reagent Blank (LRB) -- An aliquot of reagent water or other blank

matrix that is treated exactly as a sample including exposure to all glassware,

equipment, solvents, reagents, internal standards, and surrogates that are used with other samples. The LRB is used to determine if method analytes or other interferences are present in the laboratory environment, the reagents, or the

apparatus.

3.8Quality Control Sample (QCS) -- A solution of method analytes of known

concentrations which is used to fortify an aliquot of LRB or sample matrix.

The QCS is obtained from a source external to the laboratory and different

from the source of calibration standards. It is used to check laboratory

performance with externally prepared test materials.

3.9Stock Standard Solution (SSS) -- A concentrated solution containing one or

more method analytes prepared in the laboratory using assayed reference

materials or purchased from a reputable commercial source.

3.10Surrogate Analyte (SA) -- A pure analyte(s), which is extremely unlikely to be

found in any sample, and which is added to a sample aliquot in known

amounts(s) before extraction or other processing and is measured with the

same procedures used to measure other sample components. The purpose of

the SA is to monitor method performance with each sample.

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4.0INTERFERENCES

4.1Method interferences from contaminants in solvents, reagents, glassware and

other sample processing apparatus may cause discrete artifacts or elevated

baselines in gas chromatograms. All reagents and apparatus must be routinely

demonstrated to be free from interferences under the conditions of the analysis

by running laboratory reagent blanks as described in Section 9.2.

2

4.1.1Glassware must be scrupulously cleaned. Clean all glassware as soon

as possible after use by thoroughly rinsing with the last solvent used in

it. Follow by washing with hot water and detergent and thorough

rinsing with tap and reagent water. Drain dry, and heat in an oven or

muffle furnace at 400°C for one hour. Do not heat volumetric ware.

Thermally stable materials might not be eliminated by this treatment.

Thorough rinsing with acetone and methylene chloride may be

substituted for the heating. After drying and cooling, seal and store

glassware in a clean environment to prevent any accumulation of dust

or other contaminants. Store inverted or capped with aluminum foil.

4.1.2The use of high purity reagents and solvents helps to minimize

interference problems. Purification of solvents by distillation in

all-glass systems may be required.

4.2Interfering contamination may occur when a sample containing a low

concentration of ETU is analyzed immediately following a sample containing a

relatively high concentration of ETU. Thorough between-sample rinsing of the

sample syringe and associated equipment with ethyl acetate can minimize

sample cross contamination. After analysis of a sample containing high

concentrations of ETU, one or more injections of ethyl acetate should be made

to ensure that accurate values are obtained for the next sample.

4.3Matrix interferences may be caused by contaminants that are coextracted from

the sample. The extent of matrix interferences may vary considerably from

source to source, depending upon the sample. Tentative identifications must

be confirmed using the confirmation column (Section 6.7.2) and the conditions

in Table 1.

4.4Studies have shown that persistent ETU decomposition is circumstantially

linked to free radical mechanism. Addition of a free radical scavenger is

necessary to prohibit any free radical reactions.

5.0SAFETY

5.1ETU is a suspected carcinogen and teratogen. Primary standards of ETU

should be prepared in a hood. A NIOSH/MESA approved toxic gas respirator

should be worn when the analyst handles high concentrations of ETU. Each

laboratory is responsible for maintaining a current awareness file of OSHA

regulations regarding the safe handling of the chemicals specified in this

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method. A reference file of material data handling sheets should also be made

available to all personnel involved in the chemical analysis. Additional

references to laboratory safety are available and have been identified (3-5) for

the information of the analyst.

6.0EQUIPMENT AND SUPPLIES

6.1Sampling Containers -- 60 mL screw cap vials equipped with Teflon-faced

silicone septa. Prior to use, wash vials and septa with detergent and rinse

with tap and distilled water. Allow the septa to air dry at room temperature,

place in a 105°C oven for one hour, then remove and allow to cool in an area

known to be free of organics. Heat vials at 400°C for one hour to remove

organics.

6.2Glassware

6.2.1Concentrator tube, Kuderna-Danish (K-D) -- 10 mL or 25 mL,

graduated. Calibration must be checked at the volumes employed in

the test. Ground glass stoppers are used to prevent evaporation of

extracts.

6.2.2Evaporative flask, K-D -- 500 mL. Attach to concentrator tube with

springs.

6.2.3Snyder column, K-D -- Three-ball macro to which a condenser can be

connected to collect solvent.

6.2.4Vials -- Glass, 5-10 mL capacity with Teflon lined screw caps.

6.3Boiling Stones -- Carborundum, #12 granules, heat at 400°C for 30 minutes

prior to use. Cool and store in a desiccator.

6.4Water Bath -- Heated, capable of temperature control (±2°C). The bath should

be used in a hood.

6.5Balance -- Analytical, capable of accurately weighing to the nearest 0.0001 g.

6.6Tube Heater -- Capable of holding 8 K-D concentrator tubes and heating the

mid-section of the tubes to 35-40°C while applying a nitrogen stream.

6.7Gas Chromatograph -- Analytical system complete with GC equipped with a

nitrogen-phosphorus detector, split/splitless injector for capillary columns and

all required accessories. A data system is recommended for measuring peak

areas. An autoinjector is recommended to improve precision of analyses.

6.7.1Primary column -- DB-Wax or equivalent, 10 m x 0.25 mm I.D. bonded

fused silica column, 0.25 μm film thickness. Validation data presented

in this method were obtained using this column. Alternative columns

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may be used provided equal or better peak separation and peak shape

are obtained.

6.7.2Confirmation column -- DB-1701 or equivalent, 5 m x 0.25 mm I.D.

bonded fused silica column, 0.25 μm film thickness.

6.7.3Detector -- Nitrogen-phosphorus (NPD). This detector has proven

effective in the analysis of fortified reagent and artificial ground waters.

A NPD was used to generate the validation data presented in this

method. Alternative detectors, including a mass spectrometer, may be

used.

7.0REAGENTS AND STANDARDS

7.1Reagent Water -- Reagent water is defined as water in which an interference is

not observed at the retention time for ETU at the method detection limit. A

Millipore Super-Q Water System or its equivalent may be used to generate

reagent water. Water that has been charcoal filtered may also be suitable.

7.2Methylene Chloride, Ethyl Acetate -- Distilled-in-glass quality or equivalent.

7.3Nitrogen Gas -- High purity.

7.4Extraction Column, Extrelut QE -- Obtained from EM Science (Catalog

No. 902050-1). Extrelut QE columns contain a specially modified form of large

pore Kieselguhr with a granular structure.

7.5Ammonium Chloride -- Granular, ACS grade, for pH and ionic strength

adjustment of samples.

7.6Potassium Fluoride -- Anhydrous, ACS grade, for ionic strength adjustment of

sample.

7.7Dithiothreitol (DTT) (Cleland's reagent) -- For use as a free-radical scavenger

(available from Aldrich Chemical Co.).

7.7.1DTT in ethyl acetate, 1000 μg/mL -- Prepare by adding 1 g DTT to a

1 L volumetric flask and diluting to volume with ethyl acetate. Store at

room temperature.

7.8Propylene Thiourea (PTU) -- For use as a surrogate standard. Prepared from

carbon disulfide and 1,2-diaminopropane using the procedure published by

Hardtmann, et. al. (Journal of Medicinal Chemistry, 18 (5), 447-453, 1975).

7.93,4,5,6-Tetrahydro-2-pyrimidinethiol (THP) -- >98% purity, for use as an

internal standard (available from Aldrich Chemical Co.).

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7.10Artificial Ground Waters -- Two artificial ground waters were used to generate

the validation data in this method. The first was used to mimic a hard ground water, and the second used to mimic a ground water with high organic

content.

7.10.1Hard artificial ground water -- Absopure Natural Artesian Spring

Water obtained from the Absopure Water Company in Plymouth,

Michigan.

7.10.2Organic-contaminated artificial ground water -- Reagent water spiked

with fulvic acid at the 1 mg/L concentration level. A well

characterized fulvic acid, available from the International Humic

Substances Society (associated with the United States Geological Survey

in Denver, Colorado), was used.

7.11Stock Standard Solution (0.10 μg/μL) -- The stock standard solution may be

purchased as a certified solution or prepared from pure standard material

using the following procedure:

7.11.1Prepare stock standard solution by accurately weighing 0.0010 g of

pure ETU. Dissolve the ETU in ethyl acetate containing 1000 μg/mL of

DTT and dilute to volume in a 10 mL volumetric flask. Larger volumes

may be used at the convenience of the analyst. If ETU purity is

certified at 96% or greater, the weight may be used without correction

to calculate the concentration of the stock standard. Commercially

prepared stock standards may be used at any concentration if they are

certified by the manufacturer or by an independent source.

7.11.2Transfer the stock standard solution into a Teflon sealed screw cap vial.

Store at room temperature and protect from light.

7.11.3The stock standard solution should be replaced after two weeks or

sooner if comparison with laboratory control standards indicates a

problem.

7.12Internal Standard Fortifying Solution -- Prepare an internal standard fortifying

solution by accurately weighing 0.0010 g of pure THP. Dissolve the THP in

ethyl acetate containing 1000 μg/mL of DTT and dilute to volume in a 10 mL

volumetric flask. Transfer the solution to a Teflon sealed screw cap bottle and store at room temperature. Addition of 50 μL of the internal standard

fortifying solution to 5 mL of sample extract results in a final internal standard concentration of 1.0 μg/mL.

7.13Surrogate Standard Fortifying Solution -- Prepare a surrogate standard

fortifying solution by accurately weighing 0.0010 g of pure PTU. Dissolve the

PTU in ethyl acetate containing 1000 μg/mL of DTT and dilute to volume in a

10 mL volumetric flask. Transfer the solution to a Teflon sealed screw cap

bottle and store at room temperature. Addition of 5 μL of the surrogate

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standard fortifying solution to a sample prior to extraction results in a

surrogate standard concentration in the sample of 10 μg/L and, assuming

quantitative recovery of PTU, a surrogate standard concentration in the final

extract of 0.10 μg/mL.

7.14Instrument Performance Check Solution -- Prepare the instrument performance

check solution by adding 10 μL of the ETU stock standard solution, 1.0 mL of

the internal standard fortifying solution, and 100 μL of the surrogate standard

fortifying solution to a 100 mL volumetric flask and diluting to volume with

ethyl acetate containing 1000 μg/mL of DTT. Transfer the solution to a Teflon

sealed screw cap bottle and store at room temperature.

8.0SAMPLE COLLECTION, PRESERVATION, AND STORAGE

8.1Sample Collection -- Grab samples must be collected in 60 mL glass containers

fitted with Teflon-lined screw caps (Section 6.1). Conventional sampling

6

practices should be followed; however, the bottle must not be prerinsed with

sample before collection. After the sample is collected in the bottle, seal the

bottle and shake vigorously for one minute.

8.2Sample Preservation -- ETU may degrade in some samples even when the

sample is refrigerated. No suitable preservation reagent has been found other

than mercuric chloride. However, the use of mercuric chloride is not

recommended due to its toxicity and potential harm to the environment.

Previously, mercuric chloride was used to prevent only biological degradation.

Preservation tests indicate that ETU is chemically stable in aqueous samples.

Biological degradation may occur only rarely in samples with limited

biological activity such as finished drinking waters.

8.3Sample Storage -- The samples must be iced or refrigerated at 4°C and

protected from light from the time of collection until extraction. Samples

should be extracted as soon as possible after collection to avoid possible

degradation of ETU.

9.0QUALITY CONTROL

9.1Each laboratory using this method is required to operate a formal quality

control (QC) program. The minimum requirements of this program consist of

the following: an initial demonstration of laboratory capability; measurement

of the surrogate compound in each sample; analysis of laboratory reagent

blanks, laboratory fortified blanks, laboratory fortified matrix samples, and QC

check standards.

9.2Laboratory Reagent Blanks (LRB) -- Before processing any samples, the analyst

must demonstrate that all glassware and reagent interferences are under

control. This is accomplished by analyzing a LRB. A LRB is a 50 mL aliquot

of reagent water, fortified with the internal standard and the surrogate

compound, that is analyzed according to Sect. 11 exactly as if it were a sample.

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Each time a set of samples is analyzed or reagents are changed, it must be

demonstrated that the laboratory reagent blank is free of contamination that

would prevent the determination of ETU at the MDL. All interfering

contaminants must be eliminated before sample analyses are started.

9.3Initial Demonstration of Capability

9.3.1Select a representative ETU concentration about 10-20 times the MDL or

at the regulatory MCL, whichever is lower. Prepare a primary dilution

standard in ethyl acetate 1000 times more concentrated than the

selected concentration.

9.3.2Using a syringe, add 50 μL of the primary dilution standard to each of

a minimum of four 50 mL aliquots of reagent water. Also add an

appropriate amount of the internal standard and surrogate to each

sample. A representative ground water may be used in place of the

reagent water, but one or more unfortified aliquots must be analyzed to

determine background levels, and the fortified level must exceed twice

the background level for the test to be valid. Analyze the aliquots

according to the method beginning in Section 11.0.

9.3.3Calculate the measured concentration of ETU in each replicate, the

average percent recovery (R), the relative standard deviation of the

1

percent recovery (RSD), and the MDL. Ground water background

corrections must be made before R and RSD calculations are performed.

9.3.4The mean recovery value of ETU, expressed as a percentage of the true

value, must fall within ±30%, and the relative standard deviation of the

mean recovery should be less than 30%. If these conditions do not

exist, this procedure must be repeated using four fresh samples until

satisfactory performance has been demonstrated.

9.4The analyst is permitted to modify GC columns, GC conditions, or detectors to

improve the separations, identifications, or lower the cost of measurement.

Each time a modification is made, the analyst is required to repeat the

procedure in Section 9.3.

9.5Assessing Surrogate Recovery

9.5.1All samples and blanks must be fortified with the surrogate compound

according to Sectiob 11.1 before extraction to monitor preparation and

analysis of samples.

9.5.2Surrogate recovery must be evaluated for acceptance by determining

whether the measured surrogate concentration (expressed as percent

recovery) falls within the required recovery limits. Performance-based

recovery criteria for PTU has been generated from single-laboratory

results. Measured recovery of PTU must be between 70% and 130%.

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9.5.3If the surrogate recovery for a sample or blank is outside of the

required surrogate recovery limits specified in Section 9.5.2, the

laboratory must take the following actions:

(1)Check calculations to make sure there are no errors.

(2)Check internal standard and surrogate standard solutions for

degradation, contamination, or other obvious abnormalities.

(3)Check instrument performance.

Reinject the extract if the above steps fail to reveal the cause of the

problem. The problem must be identified and corrected before

continuing. Reanalyzing the sample or blank, if possible, may be the

only way to solve the problem.

9.6Assessing the Internal Standard

9.6.1The analyst is expected to monitor the internal standard peak area in all

samples and blanks during each analysis day. The IS response for any

sample chromatogram should not deviate from the IS response of the

most recent daily calibration check standard by more than 30%.

9.6.2If >30% deviation occurs with an individual extract, optimize

instrument performance and inject a second aliquot of that extract. If

the reinjected aliquot produces an acceptable IS response, report results

for that injection. If a deviation >30% is obtained for the reinjected

extract, reanalyze the sample beginning with Section 11.0, provided the

sample is still available. Otherwise, report results obtained from the

reinjected extract, but mark them as suspect.

9.6.3If consecutive samples fail the IS response acceptance criteria,

immediately analyze a medium calibration check standard. If the check

standard provides a response factor (RF) within 20% of the predicted

value, then follow procedures itemized in Section 9.6.2 for each sample

failing the IS response criteria. If the check standard provides a

response factor (RF) which deviates more than 20% from the predicted

value, then the analyst must recalibrate.

9.7Assessing Laboratory Performance

9.7.1The laboratory must analyze at least one laboratory fortified blank

(LFB) per sample set. The ETU fortifying concentration in the LFB

should be 10-20 times the MDL or the regulated MCL. Calculate the

percent recovery of the ETU. If the recovery falls outside the control

limits (see Section 9.7.2), the system is judged out of control and the

source of the problem must be identified and resolved before

continuing analyses.

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9.7.2Until sufficient LFB data become available, usually a minimum of

20-30 results, the laboratory should assess its performance against the

control limits described in Section 9.3.4. When sufficient laboratory

performance data become available, develop control limits from the

mean percent recovery (R) and standard deviation (S) of the percent

recovery. These data are used to establish upper and lower control

limits as follows:

UPPER CONTROL LIMIT = R + 3S

LOWER CONTROL LIMIT = R - 3S

After 5-10 new recovery measurements are made, control limits should

be recalculated using only the most recent 20-30 data points.

9.7.3Each laboratory should periodically determine and document its

detection limit capabilities for ETU.

9.7.4At least once each quarter, preferably more frequently, each laboratory

should analyze quality control samples. If criteria provided with the

QCS are not met, corrective action should be taken and documented.

9.7.5Each laboratory must analyze an unknown performance evaluation (PE)

sample at least once a year. ETU results must be within acceptable

limits established by the Quality Assurance Research Division of the

Environmental Monitoring Systems Laboratory, U.S. Environmental

Protection Agency, Cincinnati, Ohio.

9.8Assessing Instrument Performance -- Instrument performance should be

monitored on a daily basis by analyzing the instrument performance check

solution (IPC). The IPC contains compounds indicates appropriate sensitivity

and column performance. The IPC components and performance criteria are

listed in Table 4. Inability to demonstrate acceptable instrument performance

indicates the need for remedial action on the GC-NPD system. A

chromatogram from the analysis of the IPC is shown in Figure 1. The

sensitivity requirements are set according the MDL. MDLs will vary

somewhat in different laboratories according to instrument capabilities.

9.9Analyte Confirmation -- When doubt exists over the identification of a peak on

the chromatogram, confirmatory techniques such as chromatography with a

dissimilar column, or an alternate technique such as particle

beam/HPLC/mass spectrometry (EPA Method 553) may be used. A

suggested confirmation column is described in Table 1.

9.10Additional QC -- It is recommended that the laboratory adopt additional

quality assurance practices for use with this method. The specific practices

that are most productive depend upon the needs of the laboratory and the

nature of the samples.

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10.0CALIBRATION AND STANDARDIZATION

10.1Establish GC operating parameters equivalent to those indicated in Table 1.

Ensure that the gas chromatographic system is working properly by injecting

the instrument performance check solution (Section 7.14) and checking for

proper peak shapes, reasonable retention times, and sufficient sensitivity. The

GC system is calibrated using the internal standard technique (Section 10.2).

10.2Internal Standard Calibration Procedure -- This approach requires the analyst

to select at least one internal standard compatible in analytical behavior to the

compound of interest. The analyst must further demonstrate that the

measurement of the internal standard is not affected by method or matrix

interferences. In developing this method, THP (3,4,5,6-tetrahydro-

2-pyrimidinethiol) was found to be a suitable internal standard.

10.2.1Prepare ETU calibration standards at five concentration levels by

adding volumes of the ETU stock standard solution to five volumetric

flasks. To each flask, add a known constant amount of internal

standard and dilute to volume with ethyl acetate containing

1000 μg/mL of DTT. One of the standards should be representative of

an ETU concentration near, but above, the MDL. The other

concentrations should correspond to the range of concentrations

expected in the sample concentrates, or should define the working

range of the detector.

10.2.2Inject each calibration standard and tabulate the relative response for

ETU to the internal standard (RR) using the equation:

a

RR = A/A

a a is

where: A = the peak area of ETU.

a

A = the peak area of the internal standard.

is

Generate a calibration curve of RR versus ETU concentration in the

a

sample in μg/L.

10.2.3The working calibration curve must be verified on each working shift

by the measurement of one or more calibration standards. If the ETU

response varies from the predicted response by more than 20%, the test

should be repeated using a fresh calibration standard. Alternatively, a

new ETU calibration curve should be prepared.

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11.0PROCEDURE

11.1Sample Extraction

11.1.1Pipet a 50 mL aliquot of water sample into a sample bottle (Section 6.1)

containing 1.5 g of ammonium chloride and 25 g of potassium fluoride.

Seal bottle and shake vigorously until salts are dissolved. Fortify the

sample with 5 μL of the surrogate standard fortifying solution

(Section 7.13).

11.1.2Pour contents of bottle onto Extrelut column. Allow the column to

stand undisturbed for 15 minutes.

11.1.3Add 5 mL of 1000 μg/mL DTT in ethyl acetate to a K-D concentrator

tube equipped with a 500 mL flask.

11.1.4Add 400 mL of methylene chloride in 50-75 mL portions to the Extrelut

column and collect the eluant in the K-D apparatus (Section 11.1.3).

11.2Extract Concentration

11.2.1Conduct the following work in a fume hood which is properly vented.

Add one or two boiling stones to the K-D apparatus and attach a macro

Snyder column. Prewet the Snyder column by adding about 1 mL of

methylene chloride to the top. Attach a condenser to the Snyder

column to recover the methylene chloride as it escapes the column.

Place the K-D apparatus in a 65-70°C water bath so that the K-D tube is

partially immersed in the hot water, and the entire lower rounded

surface of the flask is bathed with hot vapor. When the apparent

volume of liquid reaches 5 mL, remove the K-D apparatus and allow it

to drain and cool for at least 10 minutes.

11.2.2Reduce the liquid volume in the K-D tube to approximately 1 mL by

placing the sample in a tube heater at 35-40°C under a stream of

nitrogen. The tube heater heats the solvent in the K-D tube at volume

markings between 1 mL and 10 mL.

11.2.3Dilute sample to 5 mL with ethyl acetate; rinse walls of K-D tube while

adding ethyl acetate. Immediately fortify the sample with 50 μL of

internal standard fortifying solution (Section 7.12). Agitate sample to

disperse internal standard. Transfer sample to a GC vial and determine

ETU by GC-NPD as described in Section 11.3. Samples should be

protected from light and analyzed within 24 hours of extraction.

Sample extracts can be stored for up to 28 days, frozen at -10°C and

protected from light.

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11.3Gas Chromatography

11.3.1Table 1 summarizes the recommended GC operating conditions.

Included in Table 1 are retention times observed using this method.

An example of the separations achieved using these conditions are

shown in Figure 1. Other GC columns, chromatographic conditions, or

detectors may be used if the requirements of Section 9.3 are met.

11.3.2Calibrate the system daily as described in Section 10.0. The standards

and extracts must be in ethyl acetate.

11.3.3Inject 2 μL of the sample extract. Record the resulting peak size in area

units.

11.3.4The width of the retention time window used to make identifications

should be based upon measurements of actual retention time variations

of standards over the course of a day. Three times the standard

deviation of a retention time can be used to calculate a suggested

window size for a compound. However, the experience of the analyst

should weigh heavily in the interpretation of chromatograms.

12.0DATA ANALYSIS AND CALCULATIONS

12.1Calculate the ETU concentration in the sample from the ETU relative response

(RR) to the internal standard using the calibration curve described in

a

Section 10.2.2.

12.2For samples processed as part of a set where the laboratory control standard

recovery falls outside of the control limits in Section 9.7.2, ETU data must be

labeled as suspect.

13.0METHOD PERFORMANCE

13.1In a single laboratory, ETU recovery and precision data from reagent water

were determined at four concentration levels. Results were used to determine

the MDL and demonstrate method range. These data are given in Table 2.

Data from the interlaboratory method validation study of this method are also

available.

13.2In a single laboratory, ETU recovery and precision data from two artificial

ground waters were determined at a single concentration level of 10 μg/L.

Results were used to demonstrate applicability of the method to different

ground water matrices. These data are listed in Table 3.

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14.0POLLUTION PREVENTION

14.1Although this method requires 400 mL methylene chloride extracting solvent

per sample, no pollution of the environment will occur due to the recovery of

the solvent during the extract concentration procedure. Very little solvent will

escape the fume hood. No other solvents are utilized in this method except for

the very small amount of ethyl acetate needed to make up calibration and

fortification standards. These small amounts of solvent pose no threat to the

environment.

14.2For information about pollution prevention that may be applicable to

laboratory operations, consult "Less is Better: Laboratory Chemical

Management for Waste Reduction" available from the American Chemical

Society's Department of Government Relations and Science Policy, 1155 16th

Street N.W., Washington, D.C. 20036.

15.0WASTE MANAGEMENT

15.1It is the laboratory's responsibility to comply with all federal, state, and local

regulations governing waste management, particularly the hazardous waste

identification rules, and land disposal restrictions. The laboratory has the

responsibility to protect the air, water, and land by minimizing and controlling

all releases from fume hoods and bench operations. Compliance is also

required with any sewage discharge permits and regulations. For further

information on waste management, consult "The Waste Management Manual

for Laboratory Personnel," also available from the American Chemical Society

at the address in Section 14.2.

16.0REFERENCES

1.40 CFR, Part 136, Appendix B.

2.ASTM Annual Book of Standards, Part 31, D3694, "Standard Practice for

Preparation of Sample Containers and for Preservation," American Society for

Testing and Materials, Philadelphia, PA, p. 679, 1980.

3."Carcinogens - Working with Carcinogens," Department of Health, Education,

and Welfare, Public Health Service, Center for Disease Control, National

Institute for Occupational Safety and Health, Publication No. 77-206,

August 1977.

4."OSHA Safety and Health Standards, General Industry," (29 CFR 1910),

Occupational Safety and Health Administration, OSHA 2206, (Revised,

January 1976).

5."Safety in Academic Chemistry Laboratories," American Chemical Society

Publication, Committee on Chemical Safety, 3rd Edition, 1979.

509-15

6.ASTM Annual Book of Standards, Part 31, D3370, "Standard Practice for

Sampling Water," American Society for Testing and Materials, Philadelphia, PA, p. 76, 1980.

509-16

17.0TABLES, DIAGRAMS, FLOWCHARTS, AND VALIDATION DATA

TABLE 1. PRIMARY AND CONFIRMATION CHROMATOGRAPHIC CONDITIONS

Retention Time (minutes)

Analyte Primary Column Confirmation Column ETU 3.5 4.5

THP (internal standard) 5.1 5.0

PTU (surrogate standard) 2.7 2.2

Primary conditions:

Column:10 m long x 0.25 mm I.D. DB-Wax bonded fused

silica column (J&W), 0.25 m film thickness

Carrier gas:He @ 30 cm/sec linear velocity

Makeup gas:He @ 30 mL/min flow

Detector gases:Air @ 100 mL/min flow; H2 @ 3 mL/min flow Injector temperature:220°C

Detector temperature:230°C

Oven temperature:220°C isothermal

Sample: 2 μL splitless; nine second split delay

Detector:Nitrogen-phosphorus

Confirmation conditions:

Column: 5 m long x 0.25 mm I.D. DB-1701 bonded fused

silica column (J&W), 0.25 m film thickness

Carrier gas:He @ 30 cm/sec linear velocity

Makeup gas:He @ 30 mL/min flow

Detector gases:Air @ 100 m:/min flow; H2 @ 3 mL/min flow Injector temperature:150°C

Detector temperature:270°C

Oven temperature:150°C isothermal

Sample: 2 μL splitless; nine second split delay

Detector:Nitrogen-phosphorus

509-17

TABLE 2. RESULTS FROM MDL AND METHOD RANGE STUDIES a Fortified Amount in

Level Blank

d e f g

(μg/L)(μg/L)n R S RSD MDL

c

5.00.4927 970.84517 2.7

b

10ND71020.8869–25ND794 1.316–100ND797 5.966–a

Studies conducted in reagent water; average recovery of PTU surrogate from seven fortified reagent water samples was 100% (RSD) was 8.5%).

b

ND = not detected.

c

Data corrected for amount detected in blank.

d

n = number of recovery data points.

e

R = average percent recovery.

f

S = standard deviation.

g

RSD = percent relative standard deviation.

509-18

509-19

TABLE 3. RESULTS FROM MATRIX EVALUATION STUDIES a

Matrix (μg/L)

n R S RSD Amount in

Blank

e f g h Hard ND 7930.3724b d

Organic-contaminated ND 7930.2533c

Samples were fortified with at the 10 μg/L level with ETU.a

Absopure Natural Artesian Spring water obtained from the Absopure Water Company in

b Plymouth, Michigan.Reagent water fortified with fulvi

c aci

d at th

e 1 mg/L concentration level. A well

c characterize

d fulvic acid, availabl

e from the International Humic Substances Society

(associated with the United States Geological Survey in Denver, Colorado), was used.ND = not detected.d n = number of recovery data points.e R = average percent recovery.f S = standard deviation.g RSD = percent relative standard deviation.

h

GB 汽车排放标准

轻型汽车污染物排放限值及测量方法（中国Ⅲ、Ⅳ阶段）Limits and measurement methods for emissions from light-duty vehicles (Ⅲ, Ⅳ) (GB 18352.3—20052007-07-01实施) 为贯彻《中华人民共和国环境保护法》和《中华人民共和国大气污染防治法》，防治机动车污染物排放对环境的污染，改善环境空气质量，制订本标准。本标准规定了装用点燃式发动机的轻型汽车，在常温和低温下排气污染物、曲轴箱污染物、蒸发污染物的排放限值及测量方法，污染控制装置的耐久性要求，以及车载诊断（OBD）系统的技术要求及测量方法。本标准规定了装用压燃式发动机的轻型汽车，在常温下排气污染物的排放限值及测量方法，污染控制装置的耐久性要求，以及车载诊断（OBD）系统的技术要求及测量方法。本标准也规定了轻型汽车型式核准的要求，生产一致性和在用车符合性的检查与判定方法。本标准也规定了燃用LPG或NG轻型汽车的特殊要求。本标准也规定了作为独立技术总成、拟安装在轻型汽车上的替代用催化转化器，在污染物排放方面的型式核准规程。本标准适用于以点燃式发动机或压燃式发动机为动力、最大设计车速大于或等于50km/h的轻型汽车。本标准不适用于已根据GB 17691（第Ⅲ阶段或第Ⅳ阶段）规定得到型式核准的N1类汽车。 解读中国轻型汽车第Ⅲ、IV阶段排放标准GB18352.3-2005 https://www.wendangku.net/doc/441406160.html, [ 2005-8-30 11:28:29 ] 来源：中国汽车动态网? 李怀斌 [推荐] [大中小] [关闭窗口] 今年4月27日，国家环保总局公布了五项机动车污染物排放新标准。其 中与广大汽车生产企业最为密切的是GB18352.3-2005《轻型汽车污染物排放限 值及测量方法(中国Ⅲ、Ⅳ阶段)》(即中国轻型汽车第Ⅲ、Ⅳ号排放标准)，轻 型汽车第Ⅲ号排放标准自2007年7月1日起实施，第Ⅳ号排放标准自2010年

美国汽车排放标准

美国汽车排放标准 美国有加州及联邦两个标准。美国加州最早控制汽车排放，而且标准也最严。1963年制订了“大气清洁法”；1966年加州制订“7工况法”，颁布汽车排放控制标准；1968年联邦采用“7工况法”开始控制汽车排放；1972年联邦采用LA-4C(FTP-72)试验规范，并增加对NO X的控制；1975年改用LA-4H(FTP-75)，并一直延续使用至今。1975年起到80年代，美国排放标准大幅度加严，特别强化对NO X的限值，同时再提高对HC和CO的控制，1983年排放标准一直维持到1993年。1990年美国国会修订了“清洁空气法”，对汽车排放提出更加严格的要求。表11-1是联邦轿车排放标准。联邦分两阶段加严排放标准，对HC的排放限制不仅指总碳氢(THC)，而要限制非甲烷碳氢化物(NMHC)，另外新标准增加对排放稳定性(使用寿命)的考核，提出8万英里和16万英里两个排放限值(见表11-2)。 美国联邦轻型车排放控制标准(g/mile) 表11-1 美国轻型汽车排放限值(FTP-75测试循环) (g／km) 表11-2 （1）微粒排放只用于柴油车 1994年加州颁布了清洁燃料和低排放汽车计划CF/LEV，规定从1995年起实施严格的低污染汽车标准（LEV），分四阶段进行：即过渡低排放车(TLEV)、低排放车(LEV)、超低排放车(ULEV)和零污染车和（ZEV）。表11-3是加州轿车排放限值。 美国加州轻型汽车排放限值(g/km) 保证里程80000km 表11-3

美国联邦49个州和加利福尼亚州的重型车用柴油机的排放限值见表11-4。 美国重型车用柴油机的排放

美国EPA通用土壤筛选值

美国EPA通用土壤筛选值

美国EPA通用土壤筛选值

CAS 号污染 物 土壤（mg/kg） 地下 （μg/L 居 住 备 注 工 业 备 注 基于 地下 水保 护 饮用 水 1 +04 E+0 5 +00 +04 75-86- 5 丙酮氰 醇 2.0E +02 n 2.1 E+0 3 n 1.2E -02 5.8E +01 75-05- 8 乙腈 8.7E +02 n 3.7 E+0 3 n 2.6E -02 1.3E +02 98-86- 2 乙酰苯 7.8E +03 ns 1.0 E+0nms 1.1E +00 3.7E +03

CAS 号污染 物 土壤（mg/kg） 地下 （μg/L 居 住 备 注 工 业 备 注 基于 地下 水保 护 饮用 水 -8 -01 E-0 1 -06 -02 79-06- 1 丙烯酰 胺 2.3E -01 c 3.4 E+0 c 9.1E -06 4.3E -02 79-10- 7 丙烯酸 3.0E +04 n 2.9 E+0 5 nm 3.7E +00 1.8E +04 107-13 -1 丙烯腈 2.4E -01 c* 1.2 E+0c* 9.9E -06 4.5E -02

CAS 号污染 物 土壤（mg/kg） 地下 （μg/L 居 住 备 注 工 业 备 注 基于 地下 水保 护 饮用 水 60-8 +00 E+0 1 -04 +00 116-06 -3 涕灭威 6.1E +01 n 6.2 E+0 2 n 9.1E -03 3.7E +01 1646-8 8-4 涕灭威 砜 6.1E +01 n 6.2 E+0 2 n 8.0E -03 3.7E +01 309-00 -2 艾氏剂 2.9E -02 c* 1.0 E-0 c 6.5E -04 4.0E -03

美国环保局 EPA 试验 方法 3520c

METHOD 3520C CONTINUOUS LIQUID-LIQUID EXTRACTION 1.0SCOPE AND APPLICATION 1.1This method describes a procedure for isolating organic compounds from aqueous samples. The method also describes concentration techniques suitable for preparing the extract for the appropriate determinative steps described in Sec. 4.3 of Chapter Four. 1.2This method is applicable to the isolation and concentration of water-insoluble and slightly soluble organics in preparation for a variety of chromatographic procedures. 1.3Method 3520 is designed for extraction solvents with greater density than the sample. Continuous extraction devices are available for extraction solvents that are less dense than the sample. The analyst must demonstrate the effectiveness of any such automatic extraction device before employing it in sample extraction. 1.4This method is restricted to use by or under the supervision of trained analysts. Each analyst must demonstrate the ability to generate acceptable results with this method. 2.0SUMMARY OF METHOD 2.1 A measured volume of sample, usually 1 liter, is placed into a continuous liquid-liquid extractor, adjusted, if necessary, to a specific pH (see Table 1), and extracted with organic solvent for 18 - 24 hours. 2.2The extract is dried, concentrated (if necessary), and, as necessary, exchanged into a solvent compatible with the cleanup or determinative method being employed (see Table 1 for appropriate exchange solvents). 3.0INTERFERENCES 3.1Refer to Method 3500. 3.2The decomposition of some analytes has been demonstrated under basic extraction conditions required to separate analytes. Organochlorine pesticides may dechlorinate, phthalate esters may exchange, and phenols may react to form tannates. These reactions increase with increasing pH, and are decreased by the shorter reaction times available in Method 3510. Method 3510 is preferred over Method 3520 for the analysis of these classes of compounds. However, the recovery of phenols may be optimized by using Method 3520 and performing the initial extraction at the acid pH. 4.0APPARATUS AND MATERIALS 4.1Continuous liquid-liquid extractor - Equipped with polytetrafluoroethylene (PTFE) or glass connecting joints and stopcocks requiring no lubrication (Kontes 584200-0000, 584500-0000, 583250-0000, or equivalent). CD-ROM3520C - 1Revision 3 December 1996

美国EPA200种潜在致癌物的危害等级

潜在致癌剂的危害等 级 致癌性是筛选优先污染物的重要依据之一，下表列出了美国EPA公布的200种致癌剂的危害等级。其中的参数含义为： 1、证据的充分程度（Degree of Evidence） 化学品对人体的致癌性证据之充分程度可以分为下列几类。 （1）证据充分，指致癌剂和人体癌症之间有因果关系。 （2）证据有限，指能提供一些可信的致癌性证据，但证据尚有限，还需作进一步补充。 （3）证据不充分，可能有3种情况，①能获取的致癌性数据很少；②与证据有关的研究尚不能排除偶然性、误差及混淆等情况；③研究结果无致癌性证据。 根据动物实验取得的致癌性证据的充分程度可分4级。 1级，致癌性证据充分。 2级，致癌性证据有限。 3级，致癌性证据不充分。 4级，无致癌性证据。 2、IARC标准分组 国际癌症研究所 （International Agency for research on cancer，简称IARC）将人类的肿瘤风险分为3组。 1组：列在此组内的化学品属致癌物，流行病学和暴露实验均已肯定，基致癌证据是充分的。 2组：化学品可能对人体有致癌性。其中有的对人体的致癌性证据几乎是“充分的”，另一类的证据不够充分。证据程度较高的为A组，较低的为B 组。例如，2A指对人体的致癌性至少存在着有限证据。当动物证据充分而人体数据不充分时，归入2B。 3组：列在本组中的化学品对人类没有致癌性。

3、潜力因素值F（Potency Factor Estimate） 潜力因素值F定义为1/ED 10。ED 10 等于10%终身致癌风险的致癌剂剂量。 F可以和致癌性的确认证据一起，用来划分化学品潜在致癌性的危险等级。 4、潜力因素分组（Potency factor Grouping） 由于潜力因素值F可表示致癌危险性的相对大小，因而，可将潜在致癌剂的相对潜力因素分为4组。潜力因素最高的化学品分在1组，中等潜力因素的为2组，低潜力因素的为3组，最低潜力因素的为4组。 5、致癌危害等级（Cancer Hazard Ranking） 根据人和动物试验所取得的致癌性证据，结合潜力因素分组数据，可将化学品致癌危害等级分为高、中、低3级。

世界汽车排放标准

各个国家有各个国家的不同啊 不能一概而论 汽车排放与欧洲标准 汽车排放是指从废气中排出的CO（一氧化碳）、HC＋NOx（碳氢化合物和氮氧化物）、PM（微粒，碳烟）等有害气体。它们都是发动机在燃烧作功过程中产生的有害气体。这些有害气体产生的原因各异，CO是燃油氧化不完全的中间产物，当氧气不充足时会产生CO，混合气浓度大及混合气不均匀都会使排气中的CO增加。HC是燃料中未燃烧的物质，由于混合气不均匀、燃烧室壁冷等原因造成部分燃油未来得及燃烧就被排放出去。NOx是燃料（汽油）在燃烧过程中产生的一种物质。PM也是燃油燃烧时缺氧产生的一种物质，其中以柴油机最明显。因为柴油机采用压燃方式，柴油在高温高压下裂解更容易产生大量肉眼看得见的碳烟。为了抑制这些有害气体的产生，促使汽车生产厂家改进产品以降低这些有害气体的产生源头，欧洲和美国都制定了相关的汽车排放标准。其中欧洲标准是我国借鉴的汽车排放标准，目前国产新车都会标明发动机废气排放达到的欧洲标准。 欧洲标准是由欧洲经济委员会（ECE）的排放法规和欧共体（EEC）的排放指令共同加以实现的，欧共体（EEC）即是现在的欧盟（EU）。排放法规由ECE参与国自愿认可，排放指令是EEC 或EU参与国强制实施的。汽车排放的欧洲法规（指令）标准1992年前巳实施若干阶段，欧洲从1992年起开始实施欧Ⅰ（欧Ⅰ型式认证排放限值）、1996年起开始实施欧Ⅱ（欧Ⅱ型式认证和生产一致性排放限值）、2000年起开始实施欧Ⅲ（欧Ⅲ型式认证和生产一致性排放限值）、2005年起开始实施欧Ⅳ（欧Ⅳ型式认证和生产一致性排放限值）。 目前在我国新车常用的欧Ⅰ和欧Ⅱ标准等术语，是指当年EEC颁发的排放指令。例如适用于重型柴油车（质量大于3.5吨）的指令“EEC88/77”分为两个阶段实施，阶段A（即欧Ⅰ）适用于1993年10月以后注册的车辆；阶段B（即欧Ⅱ）适用于1995年10月以后注册的车辆。 汽车排放的欧洲法规（指令）标准的内容包括新开发车的型式认证试验和现生产车的生产一致性检查试验，从欧Ⅲ开始又增加了在用车的生产一致性检查。 汽车排放的欧洲法规（指令）标准的计量是以汽车发动机单位行驶距离的排污量（g/km）计算，因为这对研究汽车对环境的污染程度比较合理。同时，欧洲排放标准将汽车分为总质量不超过3500公斤（轻型车）和总质量超过3500公斤（重型车）两类。轻型车不管是汽油机或柴油机车，整车均在底盘测功机上进行试验。重型机由于车重，则用所装发动机在发动机台架上进行试验。 欧盟国家努力实现对“京都议定书”的承诺，为减少汽车尾气排放污染，保护大气环境而采取的各项措施。 推广高效、低耗和低污染的“清洁汽车”，成为今年活动的焦点。欧洲各国一面不断升级汽车尾气排放标准，一面大力宣扬新的城市交通观念。但是，绝对“清洁”的汽车目前尚不存在，

美国EPA标准方法

DETERMINATION OF ETHYLENE THIOUREA (ETU) IN WATER USING GAS CHROMATOGRAPHY WITH A NITROGEN-PHOSPHORUS DETECTOR Revision 1.0 December 1992 D.J. Munch and R.L. Graves T.M. Engel and S.T. Champagne Battelle, Columbus Division ENVIRONMENTAL MONITORING SYSTEMS LABORATORY OFFICE OF RESEARCH AND DEVELOPMENT U.S. ENVIRONMENTAL PROTECTION AGENCY CINCINNATI, OHIO 45268 509-1

DETERMINATION OF ETHYLENE THIOUREA (ETU) IN WATER USING GAS CHROMATOGRAPHY WITH A NITROGEN-PHOSPHORUS DETECTOR 1.0SCOPE AND APPLICATION 1.1This method utilizes gas chromatography (GC) to determine ethylene thiourea (ETU, Chemical Abstracts Registry No. 96-45-7) in water. 1.2This method has been validated in a single laboratory during development. 1 The method detection limit (MDL) has been determined in reagent water and is listed in Table 2. Method detection limits may vary among laboratories, depending upon the analytical instrumentation used and the experience of the analyst. In addition to the work done during the development of this method and its use in the National Pesticide Survey, an interlaboratory method validation study of this method has been conducted. 1.3This method is restricted to use by or under the supervision of analysts experienced in the use of GC and in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this method using the procedure described in Section 9.3. 1.4When a tentative identification of ETU is made using the recommended primary GC column (Section 6.7.1), it must be confirmed by at least one additional qualitative technique. This technique may be the use of the confirmation GC column (Section 6.7.2) with the nitrogen-phosphorus detector or analysis using a gas chromatograph/mass spectrometer (GC/MS). 2.0SUMMARY OF METHOD 2.1The ionic strength and pH of a measured 50 mL aliquot of sample are adjusted by addition of ammonium chloride and potassium fluoride. The sample is poured onto an Extrelut column. ETU is eluted from the column in 400 mL of methylene chloride. A free radical scavenger is then added in excess to the eluate. The methylene chloride eluant is concentrated to a volume of 5 mL after solvent substitution with ethyl acetate. Gas chromatographic conditions are described which permit the separation and measurement of ETU with a nitrogen-phosphorus detector (NPD). 3.0DEFINITIONS 3.1Artificial Ground Water -- An aqueous matrix designed to mimic a real ground water sample. The artificial ground water should be reproducible for use by others. 509-2

美国EPA 第三阶段法规介绍

重庆润通2008-12-18 1 美国通机EPA 第三阶段法规新 要求介绍 天津内燃机研究所第一研究室 贾滨

重庆润通 2008-12-18 2 III, IV, V 类发动机 string trimmer chainsaw edger leaf blower Sales: 12 million/year+

重庆润通2008-12-18 3 generator walk-behind mower zero-turn mower riding mower pressure washer generator Sales: 10 million/year+ Sales: 4 million/year+ ? I 类发动机 II 类发动机

重庆润通2008-12-184 美国EPA 检查出的不符合满足法规要求 的主要方面 –标签上没有写明EPA 发动机系族名称和发动机制造商的名称; –发动机的型号没有包括在认证申报文件中; –催化器的问题:缺失或者性能达不到要求; –标签可以被完整的撕下来;– 排放标签内容有问题

重庆润通2008-12-18 5 美国EPA 对于不符合要求进口产品的策略 ?Outreach 联手 ?Target most significant violators 将目标锁定在显著违反法规的情况?Inspect and test representative samples of engines and catalysts 检查和测试有代表性的发动机和催化器样品 ?Leverage resources with Customs, Regions, States, Manufacturers, and Retailers 使用海关,地区,州,生产商和零售商的资源 ?Address the Flow of noncompliant Products 搞清楚不符合要求产品的流向 ?Upcoming North American auditing program 即将到来的北美稽查计划 ? 美国EPA 于2007年12月已经与国家质量监督检验总局签署合作备忘录, 将加强进出口产品的检验

环境空气 挥发性有机物的测定 美国EPA Method TO-1

METHOD TO-1 Revision 1.0 April, 1984 METHOD FOR THE DETERMINATION OF VOLATILE ORGANIC COMPOUNDS IN AMBIENT AIR USING TENAX? ADSORPTION AND GAS CHROMATOGRAPHY/MASS SPECTROMETRY (GC/MS) 1.Scope 1.1The document describes a generalized protocol for collection and determination of certain volatile organic compounds which can be captured on Tenax? GC (poly(2,6- Diphenyl phenylene oxide)) and determined by thermal desorption GC/MS techniques. Specific approaches using these techniques are described in the literature (1-3). 1.2This protocol is designed to allow some flexibility in order to accommodate procedures currently in use. However, such flexibility also results in placement of considerable responsibility with the user to document that such procedures give acceptable results (i.e., documentation of method performance within each laboratory situation is required). Types of documentation required are described elsewhere in this method. 1.3Compounds which can be determined by this method are nonpolar organics having boiling points in the range of approximately 80E - 200E C. However, not all compounds falling into this category can be determined. Table 1 gives a listing of compounds for which the method has been used. Other compounds may yield satisfactory results but validation by the individual user is required. 2.Applicable Documents 2.1ASTM Standards: D1356Definitions of Terms Related to Atmospheric Sampling and Analysis. E355Recommended Practice for Gas Chromatography Terms and Relationships. 2.2Other documents: Existing procedures (1-3).

gb汽车排放标准

轻型汽车污染物排放限值及测量方法（中国Ⅲ、Ⅳ阶段） Limitsandmeasurementmethodsforemissionsfr omlight-dutyvehicles(Ⅲ,Ⅳ) —20052007-07-01实施) 为贯彻《中华人民共和国环境保护法》和《中华人民共和国大气污染防治法》，防治机动车污染物排放对环境的污染，改善环境空气质量，制订本标准。本标准规定了装用点燃式发动机的轻型汽车，在常温和低温下排气污染物、曲轴箱污染物、蒸发污染物的排放限值及测量方法，污染控制装置的耐久性要求，以及车载诊断（OBD）系统的技术要求及测量方法。本标准规定了装用压燃式发动机的轻型汽车，在常温下排气污染物的排放限值及测量方法，污染控制装置的耐久性要求，以及车载诊断（OBD）系统的技术要求及测量方法。本标准也规定了轻型汽车型式核准的要求，生产一致性和在用车符合性的检查与判定方法。本标准也规定了燃用LPG或NG轻型汽车的特殊要求。本标准也规定了作为独立技术总成、拟安装在轻型汽车上的替代用催化转化器，在污染物排放方面的型式核准规程。本标准适用于以点燃式发动机或压燃式发动机为动力、最大设计车速大于或等于50km/h的轻型汽车。本标准不适用于已根据GB17691（第Ⅲ阶段或第Ⅳ阶段）规定得到

型式核准的N1类汽车。 解读中国轻型汽车第Ⅲ、IV阶 段排放标准 [2005-8-3011:28:29]来源：中国汽车动态网?李 怀斌 [][] 今年4月27日，国家环保总局公布了五项机动车污染物排放新标准。其中与广大汽车生产企业最为密切的是《轻型汽车污染物排放限值及测量方法(中国Ⅲ、Ⅳ阶段)》(即中国轻型汽车第Ⅲ、Ⅳ号排放标准)，轻型汽车第Ⅲ号排放标准自2007年7月1日起实施，第Ⅳ号排放标准自2010年7月1日起实施。 与此前国内众多汽车厂家宣称自己的车型能够达到的欧Ⅲ、欧Ⅳ排放标准不同，中国轻型汽车Ⅲ、IV号排放标准(以下简称国Ⅲ、国Ⅳ)的出台意味着以后在国内生产的轿车等轻型汽车要达到中国自己的国家标准，并按照此标准进行试验检测、型式认证。由于第Ⅲ/Ⅳ阶段轻型汽车排放法规的要求比第Ⅱ阶段严格很多，因此，随之而来的型式认证、试验类型、试验要求、试验方法、试验程序、燃油规格等方面出现了与第Ⅱ阶段完全不同的变化。这样，法规的变化、试验方法的变化必然带来试验设备的变化，政府管理方法的变化。因此无论是作为我国政府权威的汽车排放管理机构--国家环保总局，还是各汽车排放检测机构和汽车生产企业，甚至还有我国中石油、中石化两家石油业的龙头老大，这都将是

美国饮用水水质标准EPA

《美国饮用水水质标准》（EPA） [标题]：《美国饮用水水质标准》 [颁布者]：美国 [编号]： [颁布日期]： [实施日期]： [有效性]：有效 国家一级饮用水规程（NPDWRs或一级标准），是法定强制性的标准，它适用于公用给水系统。一级标准限制了那些有害公众健康的及已知的或在公用给水系统中出现的有害污染物浓度，从而保护饮用水水质。 表1将污染物划分为：无机物，有机物，放射性核素及微生物。 表1

国家二级饮用水规程：

二级饮用水规程（NSDWRs或二级标准），为非强制性准则，用于控制水中对美容（皮肤，牙齿变色），或对感官（如嗅，味，色度，）有影响的污染物浓度。 美国环保局（EPA）为给水系统推荐二级标准但没有规定必须遵守，然而，各州可选择性采纳，作为强制性标准。 表2 注： ①、污染物最高浓度目标MCLG-对人体健康无影响或预期无不良影响的水中污染物浓度。它规定了确当的安全限量，MCLGs是非强制性公共健康目标。 ②、污染物最高浓度-它是供给用户的水中污染物最高允许浓度，MCLGs它是强制性标准，MCLG是安全限量，确保略微超过MCL限量时对公众健康不产生显著风险。 ③、TT处理技术-公共给水系统必须遵循的强制性步骤或技术水平以确保对污染物的控制。 ④、除非有特别注释，一般单位为mg/L。 ⑤、1986年安全饮水法修正案通过前，未建立MCLGs指标，所以，此污染物无MCLGs值。 ⑥、在水处理技术中规定，对用铅管或用铅焊的或由铅管送水的铜管现场取龙头水样，如果所取自来水样品中超过铜的作用浓度1.3mg/L，铅的作用浓度

0.015mg/L的10%，则需进行处理。 ⑦、如给水系统采用丙烯酰胺及熏杀环（1-氯-2，3环氧丙烷），它们必须向州政府提出书面形式证明（采用第三方或制造厂的证书），它们的使用剂量及单体浓度不超过下列规定； 丙烯酰胺=0.05%，剂量为1mg/L（或相当量） 熏杀环=0.01%，剂量为20mg/L（或相当量） ⑧、地表水处理规则要求采用地表水或受地面水直接影响的地下水的给水系统，（1）进行水的消毒，并（2）为满足无须过滤的准则，要求进行水的过滤，以满足污染物能控制到下列浓度： 贾第氏虫，99.9%杀死或灭活 病毒99.99%杀死或灭活 军团菌未列限值，EPA认为，如果一旦贾第氏虫和病毒被灭活，则它就已得到控制。 浊度，任何时候浊度不超过5NTU，采用过滤的供水系统确保浊度不大于是NTU，（采用常规过滤或直接过滤则不大于0.5NTU），连续两个月内，每天的水样品中合格率至少大于95%。 HPC每毫升不超过500细菌数。 ⑨、每月总大肠杆菌阳性水样不超过5%，于每月例行检测总大肠杆菌的样品少于40只的给水系统，总大肠菌阳性水样不得超过1个。含有总大肠菌水样，要分析粪型大肠杆菌，粪型大肠杆菌不容许存在。 ⑩、粪型及艾氏大肠杆菌的存在表明水体受到人类和动物排泄物的污染，这些排泄物中的微生物可引起腹泻，痉挛，恶心，头痛或其它症状。 岳宇明译 岳舜琳校

美国EPA气体污染检测方法TO-14和TO-15的比较

Analytical Methods TO-14a and TO-15: What are the Differences?
Determining the presence of volatile organic compounds in air can be complex given the many choices available. Many options exist for sample collection (sorbent tubes, bags, filters, and canisters), as well as, a variety of analytical techniques. To assist in providing technical assistance with the options for the organic compounds EPA has available a compendia of methods in the Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air -- Second Edition (EPA/625/R-96/010b, January 1999)1. Specifically this guidance document includes two methods using the specially-treated canister: Method TO-14a and Method TO-15. Method TO-15 is a new method available in the second edition of the compendium and Method TO-14a is a revision to Method TO-14 available from the 1987 compendium. Although Methods TO-14a and TO-15 are similar, there are differences that may impact the outcome of the desired results. For sampling, Method TO-15 and Method TO-14a are identical; therefore, the analyte list and detection limit become the deciding factors when selecting the method of choice. Method Specifications Non-polar VOCs (e.g., toluene, benzene) Polar VOCs (e.g., methanol, alcohols, ketones) GC/MS instrumentation Sample collection by prepared canister (holding time = 30d) Sample collection by sorbent tube Water management techniques (avoid loss of polar compds) Enhanced provisions for quality control Method performance criteria Selected Ion Monitoring (SIM) Specific Cleaning procedures Air sample concentrated onto solid sorbent trap Use of other detectors for GC (e.g., GC/MD) Detection Limit 0.2 – 25 ppbV √ √ √ √ √ √ √ TO-14a √ TO-15 √ √ √ √ √ √ √ √ √ √ √
1
The Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air and updates can be obtained from the EPA’s OAQPS Technology Transfer Network website at http:/https://www.wendangku.net/doc/441406160.html,/ttn/amtic/airtox.html.
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Quality Assurance Team October 14, 2004

美国EPA排放法规

美国高速公路摩托车排放法规介绍 尹涛(天津大学天津摩托车技术中心) Yin Tao (Tianjin University Tianjin Motorcycle Technical center) 高速公路摩托车排放法规自1980年生效20多年来未做过修订，2002年7月，美国环保署提出了重新修订高速公路摩托车排放法规的议案，2005年正式推出了法规的修订本，其法规排放试验限值变化如表1所示。 表1 高速公路摩托车排放限值第1阶段（2006年执行） 表2 高速公路摩托车排放限值第2阶段（2010年执行） 从表中看到，新的排放法规对排量小于50 mL的摩托车提出了限值要求，并规定测试循环与原Ⅰ类摩托车测试循环相同，均为505秒的冷起阶段，864秒的过渡阶段，600秒的热浸阶段及505秒的热起阶段；Ⅰ类摩托车测试循环相对II、III类摩托车而言，最高车速要低，为58.7 km/h（36.5mph），而II、III 类摩托车测试循环最高车速为92 km/h(57.2mph)。美国环保署在调研中发现，很多排量小于50 mL的摩托车最高车速不能达到58.7 km/h，因此在很多摩托车制造商的要求下，2006年对于排量小于50 mL的摩托车，允许采用修正的Ⅰ类摩托车测试循环，即每个试验点的速度值乘以摩托车最高车速（km/h）与58.7 km/h 的比值，见图1所示。高速公路摩托车燃油蒸发限值如表3所示。 图1 高速公路摩托车测试循环

表3 EPA燃油蒸发标准（2008年执行） 以证明高速公路摩托车符合蒸发排放标准，二是通过设计声明40 CFR 1051.245（e）来证明可以达到蒸发排放标准要求。试验流程图如图2所示，设计声明格式如表4所示。 表4 设计声明符合标准 *备注:根据耐久试验情况可 以缩短静置时间 全部试验流程利用劣化系数的试验 流程

美国 EPA 方法5

METHOD 5 - DETERMINATION OF PARTICULATE MATTER EMISSIONS FROM STATIONARY SOURCES NOTE: This method does not include all of the specifications (e.g., equipment and supplies) and procedures (e.g., sampling and analytical) essential to its performance. Some material is incorporated by reference from other methods in this part. Therefore, to obtain reliable results, persons using this method should have a thorough knowledge of at least the following additional test methods: Method 1, Method 2, Method 3. 1.0 Scope and Application. 1.1 Analyte. Particulate matter (PM). No CAS number assigned. 1.2 Applicability. This method is applicable for the determination of PM emissions from stationary sources. 1.3 Data Quality Objectives. Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods. 2.0 Summary of Method. Particulate matter is withdrawn isokinetically from the source and collected on a glass fiber filter maintained at a temperature of 120 ± 14E C (248 ± 25E F) or such other temperature as specified by an applicable subpart of the standards or approved by the Administrator for a particular application. The PM mass, which includes any material that