HJ 676-2013Water quality. Determination of phenolic compounds. Liquid liquid extraction 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 phenolic compounds in water.

This standard specifies liquid-liquid extraction/gas for the determination of phenolic compounds in surface water, groundwater, domestic sewage and industrial wastewater.

Phase chromatography.

This standard is the first release.

Appendix A, Appendix B and Appendix C of this standard are informative annexes.

This standard was formulated by the Science and Technology Standards Department of the Ministry of Environmental Protection.

This standard is mainly drafted by. Ningbo Environmental Monitoring Center.

This standard is verified by. Zhoushan Marine Ecological Environment Monitoring Station, Hangzhou Environmental Monitoring Center Station, Taizhou Environment Monitoring Center Station, Jiaxing Environmental Protection Monitoring Station, Huzhou Environmental Protection Monitoring Center Station and Jinhua Environmental Monitoring Center Station.

This standard was approved by the Ministry of Environmental Protection on November 21, 2013.

This standard has been implemented since February 1, 2014.

This standard is explained by the Ministry of Environmental Protection.

Water quality - Determination of phenolic compounds - Liquid-liquid extraction/gas chromatography Warning. The solvents and reagents used in the test are all toxic. The sample preparation process should be carried out in a fume hood.

In operation, wear protective equipment as required to avoid direct contact between skin and clothing.

1 Scope of application

This standard specifies liquid-liquid extraction/gas chromatography for the determination of phenolic compounds in water.

This standard applies to surface water, groundwater, domestic sewage and industrial wastewater in phenol, 3-cresol, 2,4-xylenol, 2-Chlorophenol, 4-chlorophenol, 4-chloro-3-cresol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol, 2-nitrophenol, 4-nitrophenol 2,4-Determination of 13 phenolic compounds such as dinitrophenol and 2-methyl-4,6-dinitrophenol.

When the sampling volume is 500mL, the method detection limits and lower limit of determination of 13 phenolic compounds are shown in Table 1.

Table 1 Method detection limit and lower limit of measurement unit. µg/L

Compound name detection limit lower limit compound name detection limit lower limit Phenol 0.5 2.0 2,4,6-trichlorophenol 1.2 4.8 3-cresol 0.5 2.0 pentachlorophenol 1.1 4.4 2,4-xylenol 0.7 2.8 2-nitrophenol 1.1 4.4 2-Chlorophenol 1.1 4.4 4-Nitrophenol 1.2 4.8 4-chlorophenol 1.4 5.6 2,4-dinitrophenol 3.4 13.6 4-chloro-3-cresol 0.7 2.8 2-methyl-4,6-dinitrophenol 3.1 12.4 2,4-dichlorophenol 1.1 4.4

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.

GB/T 14581 Water quality lake and reservoir sampling technical guidance HJ/T 91 Surface Water and Wastewater Monitoring Technical Specifications HJ/T 164 Technical Specifications for Groundwater Environmental Monitoring HJ/T 493 Technical Regulations for Preservation and Management of Water Quality Samples

3 Principle of the method

Under acidic conditions (pH4 interference and elimination

4.1 There may be other organic matter interference measurement in the water sample, which can be purified by alkaline aqueous solution, or by changing color.

Spectral conditions, double column characterization or mass spectrometry were further confirmed.

4.2 There may be a memory effect after measuring a high concentration sample, which can be analyzed by blank sample until the target in the blank sample the next sample can only be analyzed if the concentration of the compound is below the lower limit of the assay.

5 Reagents and materials

Analytical purification reagents that meet national standards were used for analysis unless otherwise stated.

6 Instruments and equipment

6.1 Gas Chromatograph. With split/splitless inlet, programmable, with a hydrogen flame detector (FID).

6.2 Analytical column. quartz capillary column, 30m × 0.32mm, film thickness 0.25µm, fixed solution 5% phenyl-95% Methyl polysiloxane, or other equivalent column.

6.3 Concentrator. A concentrating device of comparable performance, such as a rotary evaporator, a nitrogen blower, or an organic sample concentrator.

6.4 Balance. Accuracy is 0.1 g.

6.5 muffle furnace.

6.6 Separating funnel. 250 mL and 1000 m L.

6.7 Microinjectors. 10 µL, 50 µL and 100 µL.

6.8 Vial. 1000 mL, brown hard glass bottle.

6.9 Common instruments and equipment used in general laboratories.

7 Samples

12 Shake the separatory funnel for about 3 to 5 minutes, and pay attention to deflation. Rest

More than 10 min, the organic phase is sufficiently separated from the aqueous phase. Transfer the aqueous phase to a 250 mL Erlenmeyer flask. Repeated back extraction of organic phase 1 the aqueous phase was combined and the phenolic compound was in the aqueous phase.

Transfer the above aqueous phase to another 250 mL separatory funnel, adjust to pH12 by using sodium hydroxide solution (5.4), and 10 g of chlorine is added.

Sodium (5.12), after shaking and dissolved, add 40 mL of dichloromethane/n-hexane mixed solvent (5.11) to extract twice, collect the aqueous phase, and then take it again.

Adjust the aqueous phase to pH8 Analysis steps

8.1 Chromatographic Reference Conditions Different models of gas chromatographs have different working conditions, and should be operated according to the instrument's instruction manual. This standard gives the chromatographic reference conditions are as follows.

Temperature programmed. 50 ° C (for 5 min) 6 ° C/min 150 ° C 20 ° C/min 280 ° C 30 ° C/min 300 ° C (guarantee Hold 2min); inlet temperature. 250 °C; FID detector temperature. 300 °C; carrier gas flow rate. 1.5 mL/min; hydrogen flow Amount. 40.0 mL/min; air flow rate. 450.0 mL/min; tail gas flow rate. 30.0 mL/min; injection method. no distinction Flow injection, purge after 1.0 min injection, purge gas flow 30.0 mL/min; injection volume. 1.0 µL.

8.2 Calibration

8.2.1 Drawing of the calibration curve Prepare a certain amount of phenolic compound standard solution (5.14) in dichloromethane/ethyl acetate mixed solvent (5.10) to prepare for the calibration series of 6 concentration points, the calibration series of each target compound is shown in Table 2. According to the chromatographic reference conditions (8.1), respectively Take 1.0 µL of the calibration series solution from the low concentration to the high concentration and analyze the peak area (or peak height) as the ordinate.

A calibration curve is drawn with the target compound concentration as the abscissa.

Table 2 Preparation of calibration curve. mg/L

No. Compound name concentration 1 concentration 2 concentration 3 concentration 4 concentration 5 concentration 6

1 Phenol 1.0 2.5 5.0 12.5 25.0 50.0 2 2-Chlorophenol 2.0 5.0 10.0 25.0 50.0 100 3 3-cresol 1.0 2.5 5.0 12.5 25.0 50.0 4 2-nitrophenol 2.0 5.0 10.0 25.0 50.0 100 5 2,4-xylenol 1.0 2.5 5.0 12.5 25.0 50.0 6 2,4-dichlorophenol 2.0 5.0 10.0 25.0 50.0 100 7 4-Chlorophenol 2.0 5.0 10.0 25.0 50.0 100 8 4-Chloro-3-cresol 1.0 2.5 5.0 12.5 25.0 50.0 9 2,4,6-trichlorophenol 2.0 5.0 10.0 25.0 50.0 100 10 2,4-dinitrophenol 5.0 12.5 25.0 62.5 125 250 11 4-nitrophenol 2.0 5.0 10.0 25.0 50.0 100 12 2-methyl-4,6-dinitrophenol 5.0 12.5 25.0 62.5 125 250

13 Pentachlorophenol 2.0 5.0 10.0 25.0 50.0 100

8.2.2 Reference standard chromatogram Under the chromatographic reference conditions given in this standard, the reference standard chromatogram of each phenolic compound on the analytical column is shown in the figure.

1-phenol, 2-2-chlorophenol, 3-3-cresol, 4-2-nitrophenol, 5-2,4-xylenol, 6-2,4-dichlorophenol, 7-4- Chlorophenol, 8-4-Chloro-3-cresol, 9-2,4,6-trichlorophenol, 10-2,4-dinitrophenol, 11-4-nitrophenol, 12-2-methyl-4,6-di Nitrophenol, 13-pentachlorophenol.

Figure 1 Standard chromatogram of phenolic compounds

8.3 Determination

Take 1.0 µL of the sample (7.2.3) and inject it into the gas chromatograph to record the retention time and peak area (or peak height) of the chromatographic peak.

8.4 Blank test

A blank test was performed during the same batch of samples. A 1.0 µL blank sample (7.3) was taken for measurement.

9 Calculation and representation of results

9.1 Target compound characterization the target compound is characterized according to the chromatogram component retention time (Rt), and if necessary, another polarity difference can be used.

The column is aided for qualitative confirmation and can be further confirmed by mass spectrometry. Chromatographic reference conditions and parameters for auxiliary qualitative columns See Appendix B for the standard chromatogram. See Appendix C for retention times for analytical and auxiliary qualitative columns.

Min10 12.5 15 17.5 20 22.5 25 27.5 pA

9.2 Calculation of results the concentration of the target compound in the water sample, irho (µg/L), is calculated according to formula (1).

××= standard rhorho (1) in the formula.

Irho - the concentration of the target compound in the water sample, µg/L;

rho - the concentration of the target compound calculated from the calibration curve, mg/L;

1V - the volume of the volume after concentration of the extract, mL;

2V - sample volume of water sample, mL.

9.3 Result representation when the measurement result is less than 10.0 µg/L, the result is retained to one decimal place; when the measurement result is greater than or equal to 10.0 µg/L the result retains three significant digits.

10 Precision and accuracy

10.1 Precision

6 laboratories have standardized spiked concentrations of 2.0 to 10.0 µg/L, 10.0 to 50.0 µg/L, and 40.0 to.200 µg/L, respectively.

The blank spiked samples were measured, and the relative standard deviations in the laboratory were. 5.8 to 19.3%, 2.3 to 16.0%, and 1.0 to 10.9 %; the relative standard deviations between laboratories are. 6.3 to 20.9 %, 9.6 to 19.0 %, 4.8 to 16.4%; reproducibility the limits are. 0.4 to 2.6 µg/L, 1.4 to 10.2 µg/L, and 5.4 to 31.3 µg/L; the reproducibility limits are. 0.4 to 4.8 µg/L, 3.3 to 17.6 µg/L, 9.7 to 47.2 µg/L.

Uniform surface water and wastewater from 6 laboratories with spiked concentrations of 10.0-50.0 µg/L and 400-2000 µg/L the spiked samples were measured, and the relative standard deviations in the laboratory were. 1.8 to 15.0%, 2.0 to 19.2%;

The relative standard deviations between the chambers were. 5.5 to 13.6% and 7.8 to 18.5%; the repeatability limits were 1.6 to 11.3 µg/L, respectively.

48.8 ~ 349 µg/L; reproducibility limits are. 1.5 ~ 15.1 µg/L, 56.5 ~ 676 µg/L.

10.2 Accuracy

6 laboratories have standardized spiked concentrations of 2.0 to 10.0 µg/L, 10.0 to 50.0 µg/L, and 40.0 to.200 µg/L, respectively.

The blank spiked samples were tested for spiked recovery. The average spiked recoveries ranged from 67.2 to 91.9% and 80.8.

94.2%, 79.5~95.1%.

The concentration of spiked water in the laboratory was 10.0~50.0 µg/L and 400~2000 µg/L, respectively.

The actual spiked samples of water were tested for spiked recovery. The average spiked recoveries ranged from 78.8 to 92.7 % and 64.9 to 84.4%.

For specific method precision and accuracy data, see Appendix A.

11 Quality Assurance and Quality Control

11.1 Qualitative analysis A retention time window of t ± 3S should be established prior to sample analysis. t is the retention time of each concentration level of reference material at the initial calibration the average value between the two, S is the standard deviation of the retention time of the standard substance at each concentration level at the initial calibration. When the sample is analyzed, the object to be tested retention time should be within the retention time window.

11.2 Blank test

Make at least 1 laboratory blank and full program blank for every 20 samples or batches (less than 20 samples/batch) the concentration of the target compound in the blank sample should be lower than the method detection limit.

11.3 Parallel sample determination for each batch of samples, 10% of parallel samples should be determined, and the relative standard deviation of the results of a single parallel test is within ±25%.

11.4 Sample spike

At least 1 blank sample plus standard and actual sample spike should be added for every 20 samples or batches of samples, and the blank sample should be spiked.

The concentration is 3 to 10 times the detection limit of the method; the concentration of the actual sample is 1 to 3 times the concentration of the sample, as in the actual sample.

The target compound was not detected and its spiked concentration was performed with reference to the blank sample. Blank sample and actual sample spike recovery should be controlled at 60 to 130%.

11.5 Calibration curve A calibration curve should be drawn for each batch of samples. The correlation coefficient of the calibration curve should be >=0.995, otherwise you should find the reason and redraw Calibration curve.

Analyze 1 curve intermediate concentration point standard solution for every 20 samples or batches of samples, and the measured results are compared with the initial curve.

The relative deviation of the measured concentration at this point should be <= 20%, otherwise the cause should be found and the calibration curve should be redrawn.

12 Waste treatment

The waste liquid generated during the experimental operation and the high concentration sample after analysis shall be entrusted to a qualified unit for proper disposal.

Appendix A

(informative appendix) Method precision and accuracy

Table A.1 gives the precision and accuracy results of the blank sample method, and Table A.2 gives the actual sample method.

Density and accuracy results.

Precision and accuracy of the method in Schedule A.1 (blank sample) Compound name Bid concentration (µg/L) average value (µg/L) Laboratory room Relative standard deviation(%) Laboratory room Relative standard deviation(%) Repeatability limit r(µg/L) Reproducibility limit R (µg/L) Spike recovery (%) Plus standard recycling end value(%) 1 phenol 2.0 1.5 8.7~11.5 14.6 0.4 0.6 68.1~96.3 76.7±22.4 10.0 8.5 4.8 to 7.5 14.0 1.4 3.3 74.0 to 107.4 85.4 ± 23.9 40.0 33.3 1.2~10.0 10.4 6.0 9.7 76.3~98.8 83.2±17.3 2 2-chlorophenol 4.0 3.1 7.3~10.8 9.0 0.8 0.8 69.7~84.1 77.3±14.0 20.0 17.0 3.3~8.8 17.4 2.9 8.3 71.9~109.9 85.2±29.7 80.0 67.5 1.4~8.6 10.9 10.1 20.6 74.4~100.3 84.4±18.4 3 3-cresol 2.0 1.5 8.2~11.3 14.4 0.4 0.6 63.8~94.4 76.8±22.0 10.0 8.5 3.2 to 8.8 15.4 1.6 3.7 68.8 to 107.0 84.8 ± 26.2 40.0 34.4 2.4~8.6 10.0 5.9 9.7 75.9~100.1 86.1±17.3 4 2-nitrophenol 4.0 3.2 7.6~10.8 12.9 0.8 1.2 66.6~95.9 79.9±20.5 20.0 16.3 2.9 to 7.8 17.9 2.7 8.2 69.6 to 107.7 81.3±29.1 80.0 67.6 1.5~10.5 11.5 11.4 21.8 72.8~99.3 84.5±19.4 5 2,4-xylenol 2.0 1.3 11.6~19.3 10.9 0.5 0.4 59.4~78.8 67.2±14.6 10.0 8.1 5.2~11.5 14.8 1.8 3.3 62.6~95.8 80.8±23.9 40.0 31.8 2.6 to 8.7 15.8 5.4 14.1 64.2 to 101.0 79.5±25.2 6 2,4-dichlorophenol 4.0 3.1 8.3~14.5 12.6 0.9 1.1 65.9~90.9 77.8±19.6 20.0 16.7 3.1~9.2 19.0 3.2 8.9 71.1~113.3 83.6±31.7 80.0 68.7 1.5~10.6 12.2 10.7 23.5 71.7~101.4 85.8±21.0 7 4-Chlorophenol 4.0 3.2 7.6~13.8 6.9 0.9 0.6 72.5~87.5 81.2±11.2 20.0 17.3 3.1 to 9.3 17.5 3.1 8.5 70.5 to 114.1 86.5 ± 30.2 80.0 70.9 1.0~10.0 10.3 11.4 20.4 78.0~102.2 88.6±18.2 8 4-chloro-3-cresol 2.0 1.6 5.8~18.6 12.7 0.5 0.6 63.8~88.8 79.7±20.2 10.0 9.4 5.9 to 10.3 15.9 2.0 4.2 78.9 to 114.2 93.7±29.7 40.0 36.7 1.2~10.8 16.4 6.6 16.9 77.2~119.3 91.8±30.1 9 2,4,6-trichlorophenol 4.0 3.7 6.6~10.6 12.1 1.0 1.2 72.5~100.9 91.4±22.2 20.0 17.8 2.3~11.2 14.3 3.4 7.1 76.2~112.6 89.1±25.5 80.0 72.2 1.6~10.5 11.0 11.3 22.1 78.6~104.1 90.2±19.8 10 2,4-dinitrophenol 10.0 8.3 7.5 to 15.1 15.0 2.6 3.5 69.9 to 105.1 83.2 ± 24.9 50.0 47.1 2.7~16.0 12.9 10.2 17.0 73.6~105.3 94.2±24.3 200 186 1.3~6.7 9.1 24.4 47.2 80.6~101.5 93.2±16.9 11 4-nitrophenol 4.0 3.5 8.5 to 12.5 9.8 0.9 1.0 80.0 to 100.3 87.6 ± 17.1 20.0 17.1 3.8 to 11.7 16.3 3.4 7.8 71.4 to 110.8 85.4 ± 27.9 80.0 73.5 2.2~10.5 4.8 12.7 9.8 86.6~97.8 91.8±8.7 Continued Compound name Bid concentration (µg/L) average value (µg/L) Laboratory room Relative standard deviation(%) Laboratory room Relative standard deviation(%) Repeatability limit r(µg/L) Reproducibility limit R (µg/L) plus.