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HJ 715-2014 English PDF

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HJ 715-2014: Water quality. Determination of polychlorinated biphenyls (PCBs). Gas chromatography mass spectrometry
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HJ 511   HJ 945.3   HJ 943   

Basic data

Standard ID HJ 715-2014 (HJ715-2014)
Description (Translated English) Water quality. Determination of polychlorinated biphenyls (PCBs). Gas chromatography mass spectrometry
Sector / Industry Environmental Protection Industry Standard
Word Count Estimation 19,119
Date of Issue 11/27/2014
Date of Implementation 1/1/2015
Regulation (derived from) Ministry of Environmental Protection Notice 2014 No. 77
Issuing agency(ies) Ministry of Ecology and Environment

HJ 715-2014: Water quality. Determination of polychlorinated biphenyls (PCBs). Gas chromatography mass spectrometry


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Water quality.Determination of polychlorinated biphenyls (PCBs).Gas chromatography mass spectrometry National Environmental Protection Standard of the People's Republic Determination of water quality polychlorinated biphenyls Gas chromatography-mass spectrometry Water quality - Determination of polychlorinated biphenyls (PCBs) - Gas chromatography mass spectrometry Published on.2014-11-27 2015-01-01 Implementation Ministry of Environmental Protection released i directory Foreword..ii 1 Scope 1 2 Normative references 1 3 Principle of the method 1 4 interference and elimination..1 5 reagents and materials..1 6 instruments and equipment..3 7 samples.3 8 Analysis step 4 9 Calculation and representation of results 6 10 Precision and Accuracy 7 11 Quality Assurance and Quality Control.7 12 Waste treatment 8 Appendix A (Normative) Name of the target compound and the limit of detection and lower limit of determination.9 Appendix B (informative) Determination of target compounds. Reference parameters.10 Appendix C (informative) method of precision and accuracy 11

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, To ensure human health, standardize the determination method of polychlorinated biphenyls in water, and formulate this standard. This standard specifies gas chromatography-mass spectrometry for the determination of 18 polychlorinated biphenyls in water. This standard is the first release. Appendix A of this standard is a normative appendix, and Appendix B and Appendix C are informative appendices. This standard was formulated by the Science and Technology Standards Department of the Ministry of Environmental Protection. This standard is mainly drafted by. Harbin Environmental Monitoring Center Station. The standard verification unit. Heilongjiang Environmental Monitoring Center Station, Dalian Environmental Monitoring Center, Changchun City Environmental Monitoring Xinzhan, Environmental Monitoring Center Station of Anshan City, Environmental Monitoring Center Station of Qiqihar City and Environmental Monitoring Center of Daqing City. This standard was approved by the Ministry of Environmental Protection on November 27,.2014. This standard has been implemented since January 1,.2015. This standard is explained by the Ministry of Environmental Protection. 1 Determination of water quality polychlorinated biphenyls - Gas chromatography - mass spectrometry Warning. PCBs are toxic, carcinogenic, teratogenic, mutagenic, avoiding entrance and contact skin skin. Organic solvents such as n-hexane used in the analysis process are toxic to the human body and should be worn by analysts. Gloves and respirator with activated carbon layer and operate in a fume hood to minimize and reduce breathing Contact and skin contact.

1 Scope of application

This standard specifies gas chromatography-mass spectrometry for the determination of 18 polychlorinated biphenyls in water. This standard applies to the determination of 18 polychlorinated biphenyls in surface water, groundwater, industrial wastewater and domestic sewage. When the sampling amount is 1L, the detection limit of the method is 1.4 to 2.2 ng/L, and the lower limit of determination is 5.6 to 8.8 ng/L. See details Appendix A.

2 Normative references

The contents of this standard refer to the following documents or their terms. For undated references, the valid version is appropriate. Used in this standard. HJ/T 91 Surface Water and Wastewater Monitoring Technical Specifications HJ/T 164 Technical Specifications for Groundwater Environmental Monitoring

3 Principle of the method

The polychlorinated biphenyls in the sample are extracted by liquid-liquid extraction or solid phase extraction, and the extract is dehydrated, concentrated, purified and fixed. The volume was separated and determined by gas chromatography-mass spectrometry. According to retention time, fragment ion mass-to-charge ratio and different ion abundance ratio Sex, internal standard method quantitative.

4 interference and elimination

The chromatographic peaks of other PCB congeners coexisting in the sample will interfere with the target compound, and 50% can be selected. Confirm with an octyl/50% methyl siloxane column or other equivalent column or use a longer capillary column.

5 reagents and materials

Unless otherwise stated, the analysis uses a superior purification reagent that meets national standards, and the experimental water is a freshly prepared steam. Distilled water. 5.1 n-hexane (C6H14). pesticide residue grade. 5.2 Methanol (CH4O). pesticide residue grade. 5.3 ethyl acetate (C4H8O2). pesticide residue grade. 5.4 Ethyl ether (C2H6O). pesticide residue grade. 5.5 Acetone (C3H6O). pesticide residue grade. 5.6 n-hexane/ethyl acetate solution. 1 1. 5.7 Sodium chloride (NaCl). heated at 450 ° C for 4 h, placed in a desiccator to cool to room temperature, sealed and stored in a clean test 2 dose bottles. 5.8 anhydrous sodium sulfate (Na2SO4). heated at 450 ° C for 4 h, placed in a desiccator to cool to room temperature, sealed and stored in dry The net is in the reagent bottle. 5.9 sodium thiosulfate (Na2S2O3). 5.10 Hydrochloric acid. ρ(HCl) = 1.18 g/ml. 5.11 Hydrochloric acid solution. 1 1. 5.12 Sulfuric acid. ρ(H2SO4) = 1.84 g/ml. 5.13 sodium hydroxide solution. ρ (NaOH) = 0.4 g/ml. Weigh 40g of sodium hydroxide, dilute to 100 ml with water, and mix. 5.14 sodium chloride solution. ρ (NaCl) = 0.05 g/ml. Weigh 5 g of sodium chloride (NaCl), dilute to 100 ml with water, and mix. 5.15 Eluent 1. 6 94 diethyl ether/n-hexane mixed solution. 5.16 Eluent 2. 1 9 acetone/n-hexane mixed solution. 5.17 standard stock solution. ρ = 1.0 μg/ml, the solvent is n-hexane. Commercially available certified standard solutions can be purchased directly. Including PCB28, PCB52, PCB101, PCB81, PCB77, PCB123, PCB118, PCB114, PCB138, PCB105, PCB153, PCB126, PCB167, PCB156, PCB157, PCB180, PCB169, PCB189. Sealed below 4°C and protected from light, or refer to the manufacturer's recommended storage conditions. 5.18 Internal standard stock solution (IS). PCB77-d6, PCB156-2 ́, 6,6 ́-d3, ρ=100.0 μg/ml. The certified standard solution can be purchased directly or prepared with standard materials and diluted with n-hexane. Below 4 ° C, sealed, avoid Save light, or refer to the manufacturer's recommended storage conditions. Other isotopically labeled internal standards can also be used. 5.19 internal standard use solution. ρ = 20.0 μg/ml. The internal standard stock solution (5.18) was diluted with n-hexane. 5.20 Standard stock of alternatives. PCB28-2 ́, 3 ́, 5 ́, 6 ́-d4, PCB114-2 ́, 3 ́, 5 ́, 6 ́-d4, ρ=100.0 μg/ml. The certified standard solution can be purchased directly or prepared with standard materials and diluted with n-hexane. Sealed at 4 ° C or less, protected from light, Or refer to the storage conditions recommended by the manufacturer. Other isotopic labeling alternatives can also be used. 5.21 Alternative standard use solution. ρ = 1.0 μg/ml. The standard stock solution of the substitute (5.20) was diluted with n-hexane. 5.22 Decafluorotriphenylphosphine (DFTPP) stock solution. ρ = 1000.0 mg/ml, the solvent is n-hexane. The certified standard solution can be purchased directly or prepared with standard materials and diluted with n-hexane. 5.23 Decafluorotriphenylphosphine (DFTPP) use solution. ρ = 50.0 mg/ml. The decafluorotriphenylphosphine (DFTPP) stock solution (5.22) was diluted with n-hexane. 5.24 quartz glass wool. Dip with n-hexane, vacuum dry and seal and store. 5.25 Flory Silica. 60 to 100 mesh. Heat at 130 ° C for 24 h, place in a desiccator and cool to room temperature, sealed and stored in a clean reagent bottle. before use preparation. 5.26 Florisil solid phase column. commercially available 1000mg, 6ml, can also choose the appropriate capacity based on the impurity content of the sample Commercialized Flory Silica solid phase column. 35.27 solid phase extraction membrane. material. octadecyl bond and silica gel; diameter 47 mm, other methods can be used if the method is satisfied Specifications solid phase extraction membrane. 5.28 Nitrogen. 99.999% for sample concentration. 5.29 hernia. 99.999%.

6 Instruments and equipment

6.1 Vials. 1L, 2L or 10L brown with a stoppered glass bottle. 6.2 Gas Chromatography-Mass Spectrometer. EI ionization source. 6.3 Column. quartz capillary column, length 30 m, inner diameter 0.25 mm, film thickness 0.25 μm, stationary phase 5% diphenyl/95% Dimethylpolysiloxane. 6.4 Solid phase extraction device. The device is suitable for extraction membrane with diameter of 47 mm, by solid phase extraction disc, suction filtration device, pump, receiving Tube composition. 6.5 Glass column. 250 mm long, 20 mm internal diameter, with Teflon piston. 6.6 Floris Silica Column. Glass column (6.4) is filled with quartz glass wool (5.24) and used as n-hexane. 10 g of activated Florisil (5.25) was wet-filled and finally filled with 1 to 2 cm of anhydrous sodium sulfate (5.8). 6.7 Dry column. glass column with a length of 250 mm and an inner diameter of 10 mm with a Teflon piston. At the lower end of the column, put less Glass wool was weighed and 10 g of anhydrous sodium sulfate (5.8) was added. 6.8 Separating funnel. 60 ml,.2000 ml with Teflon piston. 6.9 Microinjectors. 10 μl, 50 μl, 100 μl and 500 μl. 6.10 Common instruments and equipment used in general laboratories.

7 samples

7.1 Acquisition and preservation Samples were collected in accordance with the relevant regulations of HJ/T 91 and HJ/T 164. Samples should be collected in brown glass vials (6.1). The water sample is filled with sample bottles. Store at 4 ° C in the dark and extract within 7 days. 7.2 Preparation of samples 7.2.1 Extraction 7.2.1.1 Solid phase extraction This law applies only to clean water samples. Shake well and accurately measure the water sample (7.1) 1L~10L, add 100 μl substitute standard solution (5.21), mix, use The pH of the water sample is adjusted to 5~9 by hydrochloric acid solution (5.11) or sodium hydroxide solution (5.13), and 5 ml of methanol (5.2) is added per liter of sample. Mix well. Install the solid phase extraction unit in 5 ml of n-hexane/ethyl acetate solution (5.6), 5 ml of methanol (5.2) and 5 ml of experimental water activated solid phase extraction disc, after activation, the water sample was passed through solid phase extraction at a constant flow rate of 50-200 ml/min. Disc, after the sample was finished, rinse the solid phase extraction disc with 10 ml of experimental water, and continue to extract for 30 min to dry the disc. Use sequentially Solid phase extraction circle eluted with 5 ml of ethyl acetate (5.3), 5 ml of n-hexane (5.1) and 6 ml of n-hexane/ethyl acetate solution (5.6) The plate was collected and the eluate was collected. After eluating the column (6.7), it was rinsed with 6 ml of n-hexane/ethyl acetate solution (5.6). Wash the dry column and combine the eluents. The eluate was concentrated to 1 ml and n-hexane was added to 10 ml. 7.2.1.2 Liquid-liquid extraction 420 ° C/min 120 ° C (1 min) 180 ° C 5 ° C/min 280 ° C (20 min) Shake well and accurately measure the water sample (7.1) 1L to 2L separatory funnel, add 100 μl of substitute standard solution (5.21), Mix well, adjust the pH of the water sample to 5~9 with hydrochloric acid solution (5.11) or sodium hydroxide solution (5.13), add 20 g of sodium chloride. (5.7), after completely dissolving, add 60 ml of n-hexane (5.1), shake for 30 s by hand, shake for 5 min, and let stand for stratification. weight After double extraction, the combined extracts were dehydrated on a dry column (6.7), and then washed with 6 ml of n-hexane to dry the column. The liquid and eluent were taken and concentrated to 10 ml. Note 1. Exhaust gas should be carried out in a fume hood to prevent cross-contamination. Note 2. When emulsification occurs during the extraction process, it can be broken, centrifuged, filtered with glass wool or the like, or frozen. The method of breaking the milk. 7.2.2 Purification 7.2.2.1 Sulfuric acid purification Transfer 10 ml of the concentrated solution (7.2.1) into a 60 ml separatory funnel, add 10 ml of sulfuric acid (5.12), shake gently, note The gas was deflated, then shaken for 1 min, and the layer was allowed to stand and the lower layer of sulfuric acid was discarded. Repeat the above operation if there is still color in the sulfuric acid layer Until the sulfuric acid layer is colorless. The organic phase was washed by adding 30 ml of sodium chloride solution (5.14) to the separatory funnel, and the layer was allowed to stand and discarded. The aqueous phase was removed and the organic phase was dried over a dry column (6.7) and concentrated to 1 ml. Depending on the nature of the water, it can continue with Florisil Soil purification. 7.2.2.2 Floris Silica Column Purification Flush the Florisil column (6.6) with 40 ml of n-hexane (5.1) and close the piston. Concentration after purifying sulfuric acid The liquid (7.2.2.1) is transferred to the column, and the concentrate bottle is washed twice with 1-2 ml of n-hexane (5.1) and transferred to the chromatography. In the column, discard the effluent. The column was eluted with.200 ml of eluent 1 (5.15), and the elution flow rate was controlled at 2 to 5 ml/min. (The above steps always keep the liquid level above the anhydrous sodium sulfate) and receive all the eluent. Concentrate the eluent to less than 1.0 ml, add 5.0 μl of internal standard solution (5.19), then add n-hexane (5.1) Make up to 1.0 ml and transfer to the vial for analysis. The prepared samples were stored under refrigeration at 4 ° C and analyzed within 30 days. Note 3. Ether is a low boiling point solvent and should be protected during operation. 7.2.2.3 Florisil solid phase extraction column purification Rinse the solid phase extraction column (5.26) with 4 ml of n-hexane (5.1), and infiltrate for 5 min, discard the effluent, flow rate control Made at 2 ml/min. Transfer the sulfuric acid-purified concentrate (7.2.2.1) to the column and use 2 to 3 ml of n-hexane (5.1). Wash the sample concentrate bottle twice, transfer it to the SPE column, and elute the solid phase with 10 ml of eluent 2 (5.16). Take the column and receive the eluent (the above steps should always keep the liquid level above the column packing). Concentrate the eluent to less than 1.0 ml, add 5.0 μl of internal standard solution (5.19), then add n-hexane (5.1) Make up to 1.0 ml and transfer to the vial for analysis. The prepared samples were stored under refrigeration at 4 ° C and analyzed within 30 days. 7.3 Preparation of blank samples A blank sample was prepared by replacing the sample with experimental water (5.1) and following the same procedure as sample preparation (7.2).

8 Analysis steps

8.1 Instrument Reference Conditions 8.1.1 Gas Chromatography Reference Conditions Programming temperature. 5 injection method. no split injection for 1 min; Injection volume. 1.0 μl; Inlet temperature. 270 ° C; Transmission line temperature. 270 ° C; Column flow. 1.2 ml/min. 8.1.2 Mass Spectrometry Reference Conditions Ion source temperature. 250 ° C; Ionization energy. 70 eV; Full scan (Scan) mass range. 45-450 amu; Selective ion (SIM) scanning. divided into two segments, the first segment. scanning time is 9 ~ 15min, scanning ion is. 256, 264, 292, 326, 300, 334, 360; the second paragraph. the scanning time is 15 ~ 23min, the scanning ions are. 360, 365, 394. See Appendix B for ion selection. 8.2 Calibration 8.2.1 Instrument performance check The mass spectrometer was tuned with perfluorotributylamine before use. 1.0 μl of defluorination before sample analysis and every 12 h of operation Triphenylphosphine (DFTPP) is injected into the chromatograph (5.23) to check the instrument system. The mass ion abundance should be All meet the requirements in Table 1 or refer to the manufacturer's instructions. Table 1 Key ion and abundance standards of decafluorotriphenylphosphine (DFTPP) Mass-to-charge ratio (m/z) abundance standard mass ion (m/z) abundance standard 51% to 60% of the base peak 5% to 9% of the.199 base peak 68 less than 69 peaks 2% 275 base peaks 10% to 30% 70% less than 69 peaks 365 is greater than 1% of the base peak 127 40% to 60% of the base peak 441 exists and is less than 443 197 is less than 1% of the base peak 442 is greater than 40% of the base peak 198 base peak, abundance of 100% 443 442 peak 17% to 23% 8.2.2 Drawing of the calibration curve Different volumes of standard stock solution (5.17) and substitute standard use solution (5.21) were taken separately to prepare a concentration of 20.0. Standard series of 50.0, 100,.200, 500μg/L, and simultaneously add 5.0 μl of internal standard solution (5.19), diluted with n-hexane To 1.0 ml, seal and mix. According to the instrument reference conditions (8.1), the spectra of different target compounds were obtained. The ratio of the concentration of the target compound to the concentration of the internal standard compound is plotted on the abscissa, and the response value of the target compound is quantified and The ratio of the response values of the standard compound quantitative ions is plotted on the ordinate, and a calibration curve is drawn. 8.3 Sample determination The test sample (7.2) was taken and measured according to the same instrumental analysis conditions as the calibration curve. 8.4 Laboratory blank test While analyzing the sample, the blank sample (7.3) is subjected to the same instrumental analysis conditions as the calibration curve. Determination. 69 Calculation and representation of results 9.1 Qualitative analysis Data is collected in a full scan mode (Scan) to determine the relative retention time (RRT) of the target compound in the sample. The aion and target ion abundance ratio (Q) are qualitatively defined by the range of variation in the standard solution. Relative of the target compound in the sample The difference between the retention time and the calibration curve for the average relative retention time of the compound should be within ±0.06. Target compound in the sample Auxiliary Qualitative Ion and Quantitative Ion Peak Area Ratio (Q Sample) and Standard Curve Target Compound Auxiliary Qualitative Ions and Quantification The relative deviation of the ion peak area ratio (Q standard) is controlled within ±30%. Calculate the relative retention time RRT according to formula (1) Where. cRT - retention time of the target compound, min; isRT - retention time of the internal standard, min. Average Relative Retention Time (RTT). Average relative retention time of the same target compound in the standard series Calculate the ratio of auxiliary qualifier ion to quantitative ion peak area according to formula (2) (Q) Where. tA - quantitative ion peak area; qA - Auxiliary qualitative ion peak area. Selected ion scan total ion chromatograms for PCB reference materials, see Figure 1. The compounds in the figure are arranged in order of retention time. 1-PCB28-2 ́, 3 ́, 5 ́, 6 ́-d4; 2-PCB28; 3-PCB52; 4-PCB101; 5-PCB81; 6-PCB77;7-PCB77-d6;8-PCB123;9-PCB118;10-PCB114;11- PCB114-2 ́,3 ́,5 ́,6 ́-d4;12-PCB138;13-PCB105; 14-PCB153; 15-PCB126; 16-PCB167; 17-PCB156; 18- PCB156-2 ́, 6, 6 ́-d3; 19-PCB157; 20-PCB180; 21-PCB169; 22-PCB189 Figure 1 Polychlorinated biphenyl total ion flow diagram 9.2 Quantitative analysis Data was collected by selective ion scanning (SIM) and quantified by internal standard method. The mass concentration of the target in the sample i (ng/L) is calculated according to formula (3). )2(.. AQ  )1..(.. Is RT RTRRT  )3(..1000v v  Is  In the formula. i - the concentration of the polychlorinated biphenyl compound or substitute in the sample, ng/L; Is - check the concentration of the PCB compound or substitute according to the standard curve, ug/L; V-sample volume, ml; Sv - water sample volume, ml. 9.3 Result representation When the measurement result is ≥100 ng/L, the data should retain three significant figures; when the measurement result is < 100 ng/L, the data Should be retained to one decimal place. 10 Precision and accuracy 10.1 Precision Six laboratories performed precision tests on surface water spikes. The liquid-liquid extraction method was spiked at a concentration of 20.0 ng/L and 100 ng/L. And 180ng/L, the relative standard deviations in the laboratory are. 1.4% to 11%, 1.1% to 8.7%, 1.2% to 11%; experiment The relative standard deviations between the chambers were. 3.5% to 15%, 2.6% to 5.8%, and 4.2% to 17%; the repeatability limits were. 3.0 ng/L ~ 4.7 ng/L, 10.8 ng/L ~ 19.0 ng/L, 20.4 ng/L ~ 39.7 ng/L; reproducibility limits are. 3.6 ng/L ~ 23.0 ng/L, 12.8 ng/L ~ 24.9 ng/L, 28.3 ng/L ~ 83.2 ng/L. The solid phase extraction method was spiked at a concentration of 20.0 ng/L and 200ng/L, the relative standard deviations in the laboratory are. 3.4% to 13%, 4.4% to 17%; the relative standard deviation between laboratories The differences are. 2.4% to 11%, 6.4% to 15%; the repeatability limits are. 2.0 ng/L to 3.8 ng/L, 18.7 ng/L~ 30.3 ng/L; reproducibility limits range. 2.7 ng/L ~ 7.6 ng/L, 29.1 ng/L ~ 69.7 ng/L. 10.2 Accuracy Accuracy tests on groundwater spikes in six laboratories with 20 ng/L and.200 ng/L liquid-liquid extraction The average recoveries of the method are. 77.1% to 110%, 80.1% to 106%; the average recovery rates of the solid phase extraction methods are. 73.7% to 80.3%, 75.9% to 84.7%. See Appendix C for the results of precision and accuracy. 11 Quality Assurance and Quality Control 11.1 Instrument performance check The performance of the instrument shall be checked every 24 hours, and the key ions and abundance of the obtained DFTPP must all meet the requirements of Table 1. 11.2 Calibration The calibration curve requires at least 5 concentration series, and the RSD of the target compound relative response factor should be less than or equal to 20%. or The correlation coefficient of the calibration curve is greater than or equal to 0.990. Otherwise, the cause should be found or the calibration curve should be re-established. Analyze the middle concentration point of the calibration curve every 12 hours, the measured value of the intermediate concentration point and the concentration of the corresponding point of the calibration curve The relative deviation does not exceed 30%. 11.2.3 Internal standard response and retention time The peak area of each internal standard characteristic ion in the sample is to be the peak area of the internal standard characteristic ion in the same batch of continuous calibration. -50% to 100%; the retention time of each internal standard in the sample is within ± 0.50 of the corresponding internal standard retention time in continuous calibration Within min. 11.3 blank Each batch of samples should be subjected to at least one blank test, that is, a full program blank test. If the target compound is detected, it should be checked. 8 reasons. 11.4 Parallel sample determination At least 10% of the parallel samples should be determined for each batch of samples. When the number of samples is less than 10, at least one parallel double sample should be determined. When the measurement result is within 10 times the detection limit (including the detection limit of 10 times), the relative deviation of the results of the parallel double sample measurement should be ≤ 50%. When the measurement result is greater than 10 times the detection limit, the relative deviation of the results of the parallel double sample measurement should be ≤ 20%. 11.5 Determination of sample spike recovery Each batch of samples shall be tested at least once for the spiked recovery rate. The average recoveries of the actual samples shall be between 70% and 130%. 11.6 Determination of alternative recovery Substitutes are added to all samples and blanks, and the average recovery of each alternative is analyzed in the same manner as the sample. The rate should be between 70% and 130%. 12 Waste treatment The waste liquid and waste generated during the analysis should be stored in a closed container and entrusted to a qualified unit for processing.

9 Appendix A

(normative appendix) Name of target compound, detection limit and lower limit of determination Table A shows the detection limits and lower limit of determination for solid phase extraction and liquid phase extraction when the sample size is 1L. Table A Name, detection limit and lower limit of ta...

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