HJ 620-2011Water quality. Determination of volatile halogenated organic compounds. Headspace gas chromatography (English PDF)

Foreword

To implement the Environmental Protection Law of the People's Republic of China and the Law of the People's Republic of China on Water Pollution Prevention and Control, to protect the environment, this standard is formulated to ensure human health and to regulate the determination of volatile halogenated hydrocarbons in water.

This standard specifies the headspace gas chromatography for the determination of volatile halogenated hydrocarbons in water and wastewater.

This standard is a revision of the "Preparation of Volatile Halogenated Hydrocarbons by Headspace Gas Chromatography" (GB 17130-1997).

This standard was first published in 1997. The original drafting unit was China Environmental Monitoring Station. This is the first revision. repair the main contents of the subscription are as follows.

--Adopted automatic headspace injection technology;

--The target compound is increased by 1,1-dichloroethylene, dichloromethane, trans-1,2-dichloroethylene, chloroprene, cis 9 kinds of volatility of formula-1,2-dichloroethylene, 1,2-dichloroethane, monobromodichloromethane, dibromochloromethane and hexachlorobutadiene Halogenated hydrocarbons.

From the date of implementation of this standard, "Determination of volatile halogenated hydrocarbons in water quality by headspace gas chromatography" (GB/T 17130-1997) Abolition.

Appendix A and Appendix B of this standard are normative appendices.

This standard is revised by the Science and Technology Standards Department of the Ministry of Environmental Protection.

This standard is mainly drafted by. China Environmental Monitoring Center, Liaoning Provincial Environmental Monitoring Experimental Center.

This standard is verified by. Zhejiang Environmental Monitoring Center, Jilin Province Environmental Monitoring Center Station, and Shenyang Environmental Monitoring Xinzhan, Dalian Environmental Monitoring Center, Anshan Environmental Monitoring Center Station and Liaoyang Environmental Monitoring Station.

This standard was approved by the Ministry of Environmental Protection on September 1, 2011.

This standard has been implemented since November 1, 2011.

This standard is explained by the Ministry of Environmental Protection.

Water quality - Determination of volatile halogenated hydrocarbons - Gas chromatography Warning. The volatile halogenated hydrocarbon standard sample used in this method is harmful to human health and should be operated according to the requirements.

Wear protective gear to avoid contact with skin and clothing.

1 Scope of application

This standard specifies the headspace gas chromatography for the determination of volatile halogenated hydrocarbons in water.

This standard applies to surface halogen, groundwater, drinking water, seawater, industrial wastewater and volatile halogenated hydrocarbons in domestic sewage.

Determination. Specific components include 1,1-dichloroethylene, dichloromethane, trans-1,2-dichloroethylene, chloroprene, cis-1,2-Dichloroethylene, chloroform, carbon tetrachloride, 1,2-dichloroethane, trichloroethylene, monobromodichloromethane, tetrachloroethylene, two 14 kinds of bromochloromethane, tribromomethane and hexachlorobutadiene. Other volatile halogenated hydrocarbons can also be used after verification this method performs the measurement.

When the headspace bottle is 22 ml and the sampling volume is 10.0 ml, the detection limit of the above target compound is 0.02 to 6.13.

Mg/L, the lower limit of determination is 0.08 to 24.5 µg/L. See Appendix A for details.

2 Principle of the method

The water sample is placed in a sealed headspace bottle and equilibrated at a certain temperature for a certain period of time. The volatile halogenated hydrocarbon in the water Escape to the upper space and achieve a dynamic balance in the gas-liquid two phases. At this time, the concentration of volatile halogenated hydrocarbons in the gas phase and it the concentration in the liquid phase is proportional. Volatile halogenation in the gas phase using a gas chromatograph with an electron capture detector (ECD) the concentration of the hydrocarbon is measured to calculate the concentration of volatile halogenated hydrocarbons in the water sample.

3 Interference and elimination

When determining the volatile halogenated hydrocarbons in water by headspace gas chromatography, the hydrocarbons commonly found in environmental waters are not determined.

Disturb.

4 Reagents and materials

The reagents used in this standard are of analytical grade unless otherwise stated.

4.1 Experimental water. freshly prepared organic-free deionized or distilled water.

4.2 Carrier gas. high purity nitrogen, purity 99.999%.

4.3 Methanol (CH3OH). Chromatographically pure or excellent grade.

4.4 Ascorbic acid.

4.5 Sodium chloride (NaCl). excellent grade pure.

After heating at 350 ° C for 6 h, the organic matter adsorbed on the surface was removed, cooled and stored in a clean reagent bottle.

5 Instruments and equipment

5.1 with an electron capture detector (ECD) gas chromatograph.

5.2 Column. Quartz capillary column, 60 m (length) × 0.25 mm (inside diameter) × 1.4 µm (film thickness), stationary phase it is 6% cyanopropylbenzene-94% dimethylsiloxane. Or other equivalent capillary column.

5.3 Microinjectors. 10 µl, 50 µl, 100 µl, 250 µl.

5.4 1 ml airtight needle.

5.5 10 ml graduated pipette or bellows.

5.6 Brown vial. 1 ml with Teflon liner and solid screw cap.

5.7 Balance. Accuracy is 0.1 g.

5.8 Headspace bottle. 22 ml, screw or jaw top bottle, sealing cap (screw cap or gland used at one time), gasket (silicon Rubber, butyl rubber or fluoro rubber material).

5.9 Headspace bottle capper.

5.10 Sampling bottle. 40 ml, brown screw glass bottle with Teflon-lined silicone rubber pad or other similar sampling bottle.

5.11 Automatic headspace sampler. The temperature control range is from 35 to 210 °C. Other parameters are set according to the instrument instructions.

5.12 Other instruments and equipment commonly used in laboratories.

6 Samples

7 Analysis steps

14 Hexachlorobutadiene 20.0 1.00 10.0 20.0 50.0 100

1-1,1-dichloroethylene, 2-dichloromethane, 3-trans-1,2-dichloroethylene, 4-chlorobutadiene, 5-cis-1,2-dichloroethylene, 6 -three Methyl chloride, 7-carbon tetrachloride, 8-1,2-dichloroethane, 9-trichloroethylene, 10-bromodichloromethane, 11-tetrachloroethylene, 12-dibromo-Methyl chloride, 13-tribromomethane, 14-hexachlorobutadiene

Figure 1 Standard chromatogram of 14 volatile halogenated hydrocarbons

7.4 Sample determination Add 3 g of NaCl to a 22 ml headspace vial and slowly add 10.0 ml of water to the headspace vial and seal immediately.

Place in the sample tray of the headspace sampler, set the headspace sampler and GC analysis conditions, start the headspace sampler and the gas phase Chromatographic system, qualitative analysis with retention time, quantitative analysis with peak height or peak area. According to the peak area of the target, the concentration of the target in the sample solution is obtained from the calibration curve.

When the sample concentration exceeds the linear range of the calibration curve, the sample is diluted to the linear range of the calibration curve and measured.

7.5 Blank test

5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 min0 Replace the water sample with the experimental water (4.1) and measure according to step 7.4.

8 Calculation and representation of results

8.1 Calculation of results the mass concentration of the component to be tested in the sample is calculated as follows.

Irhorho

Where. rho - the mass concentration of the target compound i to be tested in the sample, µg/L;

Irho -- the mass concentration of the target compound i in the sample is found from the calibration curve, µg/L;

V - sample volume of the sample, ml.

8.2 Results representation when the result is greater than or equal to 1.00 µg/L, the result retains three significant digits; when less than 1.00 µg/L, the result remains until Two decimal places.

9 Precision and accuracy 9.1 precision

9.1.1 Surface water

Three laboratories added three different concentrations of volatile halogens of 1.00 µg/L, 5.00 µg/L, and 20.0 µg/L.

Hydrocarbon generation samples were tested. The relative standard deviation of the experimental room ranges from 0.4 to 2.9%; the relative standard deviation between laboratories the range is 0.5 to 3.5%; the repeatability limit is 0.02 to 1.27 µg/L; and the reproducibility limit is 0.03 to 1.49 µg/L.

9.1.2 Sewage

Six laboratories added volatilization at three different concentrations of 1.00 µg/L, 5.00 µg/L, and 20.0 µg/L.

The halohydrocarbon samples were tested. The relative standard deviation of the experimental room ranges from 0.3 to 3.0%; the relative standard deviation between laboratories the difference range is 0.6 to 12%; the repeatability limit is 0.02 to 1.54 µg/L; and the reproducibility limit is 0.04 to 2.43 µg/L.

9.2 Accuracy

Six laboratories measured surface water and sewage matrix spiked samples.

9.2.1 Surface water

The spiked water samples were spiked at concentrations of 5.00 µg/L and 20.0 µg/L. The recoveries of the 14 target compounds were in the range of 89.7 ~ 112%.

9.2.2 Sewage

Sewage samples were spiked at concentrations of 5.00 µg/L and 20.0 µg/L, except for hexachlorobutadiene (46.6 to 50.4%).

The spiked recoveries of the target compounds ranged from 85.8 to 106%.

The summary data of precision and accuracy is detailed in Appendix B.

10 Quality Assurance and Quality Control

10.1 Blank sample

At least one laboratory blank should be made for each batch of (20) samples, and the blank test results should be less than 2 times.

Out of limits.

10.2 Parallel samples at least 10% of the parallel samples were determined for each batch (20 samples) of the analysis, and the relative deviation of the parallel samples was within 30%.

10.3 Sample addition recovery test at least one spiked recovery test is performed for each batch of samples (20 samples); the actual sample spike recovery rate is 80-120%.

between.

If the sample has a matrix effect and the spike recovery rate does not meet the requirements, then the sample spike should be analyzed. Sample plus the relative deviation of the standard and sample spike repeats should be less than or equal to 25%.

10.4 Qualitative analysis the retention time of the sample is compared to the retention time of the standard sample. Used as a qualitative retention time window width Based on the actual retention time change of the standard sample measured on the day. The retention time deviation of the target compound should not exceed 30 second.

10.5 Calibration

A calibration curve intermediate concentration standard should be analyzed for every 20 samples or 1 batch (less than 20 samples) the deviation between the measured value and the concentration value should be within 20%.

11 Precautions

11.1 Intermittent analysis of high concentration samples and low concentration samples will cause interference. When analyzing high concentration samples, a blank should be analyzed.

Prevent cross contamination.

11.2 The headspace bottle can be reused. The washing method is. washing with detergent, and then washing with tap water and distilled water several times in turn, Finally, it was baked at 105 ° C for 1 hour, taken out and allowed to cool, and placed in an organic reagent-free area for storage.

11.3 The gasket should be cleaned and dried before use, but the oven temperature should be below 60 °C. The cleaned gasket is clean Store in aluminum foil sealed bags or clean glass reagent bottles.

Appendix A

(informative appendix) Method detection limit and lower limit of determination

Table A gives the detection limits and lower limit of determination of the target compounds in the method.

Table A The detection limit and lower limit of the method

No. Compound Name English Name CAS Number the detection limit (µg/L) Lower limit of measurement (µg/L) 1, 1,1-dichloroethylene 1,1-dichloroethene 75-35-4 2.38 9.52 2 methylene chloride 75-09-2 6.13 24.5 3 trans-1,2-dichloroethylene Trans-1,2-dichloroethene 156-60-5 2.52 10.1 4 chloroprene chlorobutadiene 126-99-8 0.36 1.44 5 cis-1,2-dichloroethylene cis-1,2-dichloroethene 156-59-2 1.38 5.52 6 chloroform 67-66-3 0.02 0.08 7 carbon tetrachloride carbon tetrachloride 56-23-5 0.03 0.12 8 1,2-dichloroethane 1,2-dichloroethane 107-06-2 2.35 9.40 9 trichloroethylene 79-01-6 0.02 0.08 10 bromodichloromethane 75-27-4 0.02 0.08 11 tetrachloroethylene 127-18-4 0.03 0.12 12 dibromochloromethane 124-48-1 0.02 0.08 13 tribromomethane bromoform 75-25-2 0.04 0.16

14 Hexachlorobutadiene 87-68-3 0.02 0.08 Appendix B (informative appendix) Method precision and accuracy Tables B.1 and B.2 give the precision and accuracy indicators such as repeatability, reproducibility and spike recovery.

Table B.1 Precision and accuracy of the method (surface water)

Compound name average (µg/L) Laboratory interior Standard deviation (%) Interlaboratory phase Standard deviation (%) Repeatability limit r(µg/L) Reproducibility limit R (µg/L) Spike recovery (%) Spike recovery Final value (%) SP 2± 1.05 1.0 3.5 0.17 0.19 - -5.05 1.9 1.7 0.45 0.48 99.8~104 100±4 1,1-dichloroethylene 19.8 0.6 1.7 1.17 1.44 97.1~102 98.9±3.6 1.03 2.7 3.0 0.15 0.17 - -5.68 0.8 2.1 0.33 0.45 93.6~112 100±14 dichloromethane 20.0 0.7 1.1 0.98 1.10 89.7~101 96.5±7.5 1.01 1.0 0.8 0.05 0.05 - -5.19 1.0 0.9 0.30 0.31 103~106 104±3 trans-1,2-dichloroethylene 20.2 0.7 1.2 0.69 0.93 98.5~102 100±3 1.01 0.9 0.8 0.04 0.04 - -5.09 0.9 1.0 0.31 0.32 100~103 101±3 chloroprene 20.1 0.4 1.0 0.50 0.74 98.6~102 100±3 1.02 1.7 0.9 0.04 0.05 - -5.10 0.9 0.7 0.23 0.23 101~103 102±1.50 cis-1,2-dichloroethylene 20.0 0.5 0.7 0.53 0.63 98.9~101 102±1.50 1.01 0.7 0.6 0.02 0.03 - -5.07 0.8 0.8 0.19 0.21 97.2~99.7 98.1±1.7 Trichloromethane 20.0 0.5 0.9 0.44 0.67 97.3~99.8 99.0±1.9 1.02 0.9 0.6 0.03 0.03 - -5.25 1.2 3.0 0.23 0.50 91.4~100 96.4±7.5 Carbon tetrachloride 19.8 0.5 2.2 0.47 1.31 92.6~98.7 97.2±4.7 1.00 1.7 0.8 0.05 0.05 - -4.90 0.7 1.6 0.43 0.45 95.3~100 98.1±3.3 1,2-dichloroethane 20.0 1.2 1.6 1.27 1.47 95.0~102 100±6 1.01 0.9 0.5 0.03 0.03 - -5.10 1.1 0.7 0.23 0.24 101~103 101±3 trichloroethylene 19.9 1.0 0.8 0.60 0.72 98.2~101 99.5±1.9 1.02 0.9 0.5 0.03 0.03 - -5.12 0.8 0.8 0.16 0.19 101~103 102±2 monobromodichloromethane 20.1 0.8 0.7 0.54 0.64 100~102 100±2 1.00 1.1 0.6 0.04 0.04 - -5.19 0.6 1.8 0.32 0.40 102~106 103±4 Tetrachloroethylene 19.8 1.1 1.0 0.78 0.89 97.5~100 98.9±1.9 1.02 0.8 0.6 0.04 0.04 - -5.13 1.4 1.0 0.30 0.31 101~104 102±3 dibromochloromethane 20.1 0.9 1.0 0.57 0.76 99.5~102 100±3 1.05 1.5 1.6 0.11 0.11 - -5.19 1.4 2.5 0.42 0.53 102~106 104±4 tribromomethane 20.2 2.4 1.8 1.16 1.49 99.1~103 100±4 0.98 2.1 1.3 0.09 0.09 - -5.18 2.9 2.2 0.47 0.53 101~106 103±4 Hexachlorobutadiene 19.2 0.8 0.9 0.81 0.89 95.0~97.5 96.2±1.8

Table B.2 Precision and accuracy of the method (sewage)

Compound name average (µg/L) Laboratory interior Standard deviation (%) Interlaboratory phase Standard deviation (%) Repeatability limit r(µg/L) Reproducibility limit R (µg/L) Spike recovery (%) Spike recovery Final value (%) SP 2± 1.12 1.2 4.1 0.18 0.21 - -4.84 1.8 1.3 0.26 0.30 94.0~97.9 95.7±3.3 1,1-dichloroethylene 19.6 0.6 2.0 0.87 1.34 94.7~100 97.2±3.9 1.41 2.7 12.1 0.33 0.57 - -5.19 1.6 2.9 0.31 0.52 98.2~106 101±5.5 methylene chloride 18.6 0.9 4.2 1.04 2.38 85.8~93.1 90.6±5.6 1.01 1.0 0.8 0.04 0.05 - -5.10 1.2 1.1 0.35 0.36 101~105 102±3 trans--1,2-dichloroethylene 19.6 0.7 2.5 1.01 1.66 93.7~102 97.8±5.8 1.01 0.9 0.8 0.04 0.04 - -4.92 1.8 2.1 0.26 0.37 96.2~102 98.4±4.3 chloroprene 19.6 0.9 2.6 0.79 1.58 93.9~101 97.5±5.0 1.02 1.7 0.6 0.05 0.05 - -5.07 1.1 0.8 0.19 0.21 101~104 102±3 cis-1,2-dichloroethylene 19.1 0.8 2.9 1.08 1.82 91.7~98.1 95.1±4.7 2.22 0.3 3.5 0.02 0.22 - -5.49 1.0 5.2 0.59 0.97 87.7~94.4 89.9±4.9 chloroform 19.6 0.8 2.5 1.35 1.84 88.9~95.6 92.3±4.9 1.06 1.7 2.7 0.03 0.09 - -4.93 0.8 3.4 0.20 0.51 93.9~104 98.1±8.2 Carbon tetrachloride 20.2 1.7 3.8 1.23 2.43 95.8~105 100±8 2.23 0.4 4.6 0.05 0.30 - -5.68 1.3 9.6 0.60 1.63 88.7~97.0 93.3±6.4 1,2-dichloroethane 19.9 1.4 3.2 1.02 2.02 89.4~98.0 93.2±6.9 1.13 0.8 1.2 0.03 0.05 - -5.06 1.4 1.2 0.20 0.26 97.2~100 99.2±3.3 Trichloroethylene 19.5 0.7 2.2 0.94 1.48 93.2~99.5 96.5±4.4 1.15 0.8 0.8 0.04 0.04 - -5.11 1.1 0.6 0.17 0.18 98.7~102 100±3 monobromodichloromethane 19.1 0.9 2.0 0.97 1.40 91.2~95.9 93.6±4.2 1.26 0.9 0.8 0.04 0.05 - -5.19 0.9 2.4 0.24 0.42 96.2~103 99.2±5.6 Tetrachloroethylene 19.7 0.7 2.6 1.02 1.73 93.5~101 97.4±5.4 1.07 1.1 2.8 0.03 0.09 - -5.12 1.7 1.2 0.19 0.24 99.0~104 101±4 dibromochloromethane 18.9 0.4 1.7 1.35 1.54 91.9~95.7 93.9±3.3 1.19 2.8 8.5 0.11 0.31 - -5.21 1.7 1.8 0.21 0.33 96.4~102 100±5 tribromomethane 19.0 0.6 1.7 1.54 1.67 92.2~96.4 94.2±3.2 0.98 2.1 1.5 0.09 0.09 - -2.42 3.0 2.2 0.29 0.31 48.4~50.4 48.9±1.6 Hexachlorobutadiene 9.57 1.0 2.1 0.88 0.98 46.6~49.0 47.8±2.0