HJ 975-2018Solid waste - Determination of benzene and its analogies - Headspace-gas chromatography (English PDF)

6.1 Sample collection and preservation

6.1.1 Collect and store solid waste samples in accordance with the relevant provisions of HJ/T 20 and HJ/T 298. With a shovel and not the rust steel spoon (5.7) quickly collects the sample into the sampling bottle (5.6) and fills it as much as possible. Quickly remove the sampling bottle thread the sample adhered to the outer surface immediately seals the sample bottle. Place the sample bottle in a portable freezer (5.8) at 4 ° C Save it and bring it back to the lab.

36.1.2 Samples should be analyzed as soon as they are sent to the laboratory. If it cannot be analyzed immediately, it should be sealed and stored below 4 °C.

The limit is no more than 14 days. The sample storage area should be free of target interference.

Note. Do not excessively agitate solid waste during sample collection to avoid volatilization of benzene in the sample.

6.2 Preparation of samples

6.2.1 Preparation of solid waste samples

6.2.1.1 Low content sample

Weigh 2 g (accurate to 0.01 g) into the headspace bottle (5.11) and quickly add 10.0 ml to the headspace bottle.

And sodium chloride solution (4.5), immediately sealed, and oscillated at 150 times/min for 10 min on a reciprocating oscillator (5.4).

To be tested.

6.2.1.2 High content sample

If the target content is greater than 1000 µg/kg, it should be considered as a high-content sample. The high content sample is prepared as follows. take out the sample Bottle, weigh 2 g (accurate to 0.01 g) sample into the headspace bottle (5.11), quickly add 10.0 ml to the headspace bottle the alcohol (4.2) was immediately sealed and oscillated on a reciprocating oscillator (5.4) at a frequency of 150 times/min for 10 min. Resting After the drop, pipette approximately 1 ml of the methanol extract into a 2 ml brown compact bottle (5.10). The extract can be placed in a freezer at 4 ° C Saved below, the shelf life is 14 days.

After returning the extract to room temperature before analysis, add 2 g (accurate to 0.01 g) to the empty headspace vial (5.11) Quartz sand (4.9), 10.0 ml saturated sodium chloride solution (4.5) and 10~100 µl methanol extract, immediately sealed, in the the compound oscillator (5.4) was oscillated at a frequency of 150 times/min for 10 min to be tested.

Note 1. If the concentration of benzene in the methanol extract is high, it can be diluted with methanol.

Note 2. If the content is too low or not detected by the high content method, the sample should be re-analyzed using the low content method.

6.2.2 Preparation of solid waste leachate

Preparation of solid waste water leaching solution according to HJ/T 299; preparation of solid waste acetic acid leaching solution according to HJ/T 300 kind.

6.3 Preparation of blank samples

6.3.1 Full program blank sample

10.0 ml of saturated sodium chloride solution (4.5) and 2 g (accurate to 0.01 g) of quartz sand (4.9) in the laboratory before sampling Put it in the headspace bottle (5.11), take it to the sampling site, unpack it, seal it, and then transport it back to the laboratory with the sample.

It was oscillated on a reciprocating oscillator (5.4) at a frequency of 150 times/min for 10 min to be tested.

6.3.2 Laboratory blank sample

6.3.2.1 Solid waste low content blank sample

Weigh 2 g (accurate to 0.01 g) quartz sand (4.9) instead of low content, and prepare low content according to 6.2.1.1 Blank sample.

46.3.2.2 Solid waste high content blank sample

Weigh 2 g (accurate to 0.01 g) quartz sand (4.9) instead of high-content samples, and prepare high content according to 6.2.1.2 Blank sample.

6.3.2.3 Blank sample of solid waste leachate A blank sample of the leachate was prepared in the same manner as the solid waste leachate preparation (6.2.2).

7 Analysis steps

7.1 Headspace Sampler Reference Conditions Heating equilibrium temperature 85 ° C; heating equilibrium time 50 min; sampling needle temperature 100 ° C; transmission line temperature 110 ° C; pressure the equilibrium time was 1 min; the injection time was 0.2 min; the needle removal time was 0.4 min.

7.2 Gas Chromatograph Reference Conditions Temperature programming. 40 ° C for 6 min, ramp up to 110 ° C at 5 ° C/min, for 1 min, then 6 ° C the heating rate of /min is raised to.200 ° C for 3 min; the inlet temperature is 220 ° C; the detector temperature is 240 ° C; carrier gas.

Nitrogen; column flow. 1.0 ml/min; hydrogen flow. 40 ml/min; air flow. 400 ml/min; injection method. minute Flow injection; split ratio. 10.1.

A standard chromatogram of the nine benzene series is shown in Figure 1.

1-benzene; 2-toluene; 3-ethylbenzene; 4-p-xylene; 5-m-xylene; 6-isopropylbenzene; 7-o-xylene; 8-n-propylbenzene; 9-styrene .

Figure 1 9 benzene series standard chromatogram

7.3 Establishment of the working curve

7.3.1 Establishment of solid waste working curve Add 2 g (accurate to 0.01 g) of quartz sand (4.9), 10.0 ml of saturated sodium chloride to the headspace bottle (5.11).

Liquid (4.5), then add 0 µl, 5 µl, 10 µl, 20 µl standard solution 1 (4.7) and 5 µl, 10 µl to each bottle.

20 µl of standard use solution 2 (4.8), immediately sealed, the target compound mass is 0 µg, 0.05 µg, 0.10 µg, A 7-point working curve series of 50.20 µg, 0.50 µg, 1.00 µg, and 2.00 µg. Prepare a sample of the prepared working curve series at the reciprocating oscillator (5.4) is oscillated at a frequency of 150 times/min for 10 min, according to the instrument reference conditions (7.1 and 7.2).

From the low content to the high content, the sample is injected sequentially, and the target compound mass (µg) is taken as the abscissa, and the peak area or peak height is the vertical position.

Mark, establish a working curve.

7.3.2 Establishment of working curve of solid waste leachate Add 10.0 ml of leaching agent to the headspace bottle (5.11), and then add 0 µl, 5 µl, 10 µl to each bottle.

20 µl standard use solution 1 (4.7) and 5 µl, 10 µl, 20 µl standard use solution 2 (4.8), immediately sealed to prepare the target Compound concentrations were 0 µg/L, 5.0 µg/L, 10.0 µg/L, 20.0 µg/L, 50.0 µg/L, 100 µg/L and.200 µg/L 7-point work curve series. According to the instrument reference conditions (7.1 and 7.2), the samples are injected sequentially from low to high concentrations.

The working curve is established by taking the target compound concentration (µg/L) as the abscissa and the peak area or peak height as the ordinate.

7.4 Sample determination Place the sample (6.2) on the headspace sampler (5.3) and follow the same instrument strip as the establishment of the working curve (7.3).

The sample was measured.

7.5 Blank test

Place the blank sample (6.3) on the headspace sampler (5.3) and follow the same instrument conditions as the sample measurement (7.4).

The measurement of the blank sample was carried out.

8 Calculation and representation of results

8.1 Calculation of results of benzene series content in solid waste

8.1.1 Calculation of results of benzene series content in low-content solid waste the benzene content w in the low-content solid waste is calculated according to the formula (1).

Where. w--the content of the target compound in the sample, mg/kg;

M0 - calculate the mass of the target compound based on the working curve, µg;

M1 - sample size (wet weight), g.

8.1.2 Calculation of results of benzene series content in high content solid waste the benzene content in the high-content solid waste is calculated according to formula (2).

SVm

Where. w--the content of the target compound in the sample, mg/kg;

M0--calculate the mass of the target compound according to the working curve, µg;

6V--the volume of the methanol extract, ml;

M1--sample amount (wet weight), g;

Vs--the volume of methanol extract used for headspace determination, ml;

f -- the dilution factor of the extract.

8.2 Calculation of the results of benzene concentration in solid waste leachate when the solid waste leachate sample is measured, the concentration of the benzene series is directly obtained from the working curve and expressed in µg/L.

8.3 result representation the number of decimal places and the method detection limit are consistent, and up to three significant digits are reserved.

9 Precision and accuracy 9.1 precision Six laboratories for wastewater treatment plants with content levels of 0.025 mg/kg, 0.100 mg/kg and 0.500 mg/kg the waste sediment samples were subjected to 6 replicate measurements. the relative standard deviations in the laboratory ranged from 3.6% to 20%, 4.3%~19% and 3.0%~20%; the relative standard deviation between laboratories is 5.9%~13%, 4.1%~9.3% and 1.8%~4.7%; repeatability limits are 0.004~0.012 mg/kg, 0.017~0.037 mg/kg and 0.087~0.165 respectively the reproducibility limits ranged from 0.004 to 0.019 mg/kg, 0.019 to 0.044 mg/kg, and 0.093 to 0.174 mg/kg, respectively.

Six laboratories for waste sludge treatment plants with concentration levels of 5.0 µg/L, 20.0 µg/L and 100 µg/L the water leaching sample was subjected to 6 repeated measurements. the relative standard deviations in the laboratory ranged from 1.2% to 14%, 0.88%~6.1% and 0.53%~4.7%; the relative standard deviation between laboratories is 2.8%~6.2%, 1.2%~5.9% and 0.78%~4.2%; repeatability limits are 0.6~1 µg/L, 1~2.4 µg/L and 6.4~8.6 µg/L, respectively; reproducibility limits They are 0.8~2 µg/L, 1.8~4 µg/L and 7.5~13.5 µg/L, respectively.

Six laboratories for waste sludge treatment plants with concentration levels of 5.0 µg/L, 20.0 µg/L and 100 µg/L the acetic acid leaching sample was subjected to 6 repeated measurements. the relative standard deviations in the laboratory ranged from 2.2% to 9.7%, 1.8%~9.8% and 0.88%~8.7%; the relative standard deviations between laboratories ranged from 3.3% to 8.7% and 1.8% to 4.2%, respectively.

1.8%~6.0%; repeatability limits are 0.7~1 µg/L, 1~2.8 µg/L and 7.3~12.6 µg/L, respectively; reproducibility limit range They are 0.8~2 µg/L, 2~3.5 µg/L and 10.6~18 µg/L, respectively.

See Appendix B for precision data.

9.2 Accuracy

Six laboratories for sewage treatment plants with spiked contents of 0.025 mg/kg, 0.100 mg/kg and 0.500 mg/kg the samples of discarded sediments were analyzed by spike analysis. the recoveries ranged from 34.8% to 71.8%, 42.3% to 70.7%, and 65.7%~94.0%; the final recoveries of the spiked recovery were 39.1%±8.6%~67.2%±7.9%, respectively.

49.1% ± 7.1% ~ 64.1% ± 8.1% and 68.9% ± 4.8% ~ 89.8% ± 5.2%.

Six laboratories for waste sludge treatment at concentrations of 5.0 µg/L, 20.0 µg/L and 100 µg/L the samples of water leaching were analyzed by spike analysis. the recoveries ranged from 78.1% to 96.8% and 82.9% to 103%, respectively.

90.2%~104%; the final recoveries were 83.0%±6.8%~91.3%±6.8%, 92.4%±12%~99.8%±3.1% 7 and 95.3% ± 3.6% to 99.8% ± 4.7%.

Six laboratories for waste sludge treatment at concentrations of 5.0 µg/L, 20.0 µg/L and 100 µg/L the samples of acetic acid leaching were analyzed by spike analysis. the recoveries ranged from 79.6% to 99.0% and 83.1% to 108%, respectively.

And 87.1%~104%; the final recoveries of the spiked recovery are 86.1%±13%~93.2%±6.8%, respectively.

86.3%±6.5%~103%±7.3% and 93.9%±7.6%~ 97.9%±6.7%.

See Appendix B for accuracy data.

10 Quality Assurance and Quality Control

10.1 Blank test

A full program blank sample and a laboratory blank should be analyzed for every 20 samples or batches (less than 20/batch) for the sample, the target compound content in the measurement results should be lower than the method detection limit.

10.2 Working curve

The working curve is drawn according to the concentration and response value of the target, and the correlation coefficient should be >=0.995.

10.3 Calibration Confirmation for every 20 samples or every 24 h, use the middle point of the working curve to confirm the calibration. The measured value of the target compound and the initial value the ratio of the initial value should be in the range of 80% to 120%. Otherwise, the work curve should be redrawn.

10.4 Parallel samples A parallel sample should be analyzed for every 20 samples or batches (less than 20/batch).

The deviation is <= 20%.

10.5 Matrix addition A blank spiked sample and matrix spiked sample should be analyzed for every 20 samples or batches (less than 20/batch), empty the recovery rate of the target in the white sample should be 70%~120%, and the recovery rate of the target in the actual sample should be 30%~135%.

Otherwise, the sample should be reanalyzed.

11 Waste treatment

The waste generated by the experiment shall be stored in a classified manner, stored in a centralized manner, and entrusted to a qualified unit for processing.

8 Appendix A

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

Table A.1 gives the method detection limits and lower limit of determination for 2 g solid waste and 10 ml solid waste leachate.

Table A.1 Detection limits and lower limit of determination of the method

Compound name English name Solid waste solid waste leachate the detection limit (mg/kg) Lower limit of measurement (mg/kg) the detection limit (µg/L) Lower limit of measurement (µg/L) 1 benzenebenzene 0.005 0.020 0.7 2.8 2 toluene 0.005 0.020 2 8 3 ethylbenzene 0.005 0.020 0.9 3.6 4 p-xylene p -xylene 0.004 0.016 0.7 2.8 5 m-xylene m -xylene 0.005 0.020 0.9 3.6 6 cumene isopropylbenzene 0.004 0.016 0.7 2.8 7 o-xylene 0.005 0.020 1 4 8 n-propylbenzene 0.004 0.016 1 4 9 styrene 0.006 0.024 0.7 2.8

9 Appendix B

(informative appendix) Method precision and accuracy Tables B.1 to B.6 show the precision of solid waste, solid waste water leachate and solid waste acetic acid leachate, respectively.

Degree and accuracy data.

Table B.1 Precision of the solid waste method

Serial number

Compound

name

content

(mg/kg)

Experimental room relative standard deviation(%) Interlaboratory standard deviation(%) Repeatability limit r (mg/kg) Reproducibility limit R (mg/kg) 1 benzene 0.017 5.5~19 5.9 0.005 0.006 0.064 4.3~14 6.3 0.017 0.019 0.432 6.8~12 1.8 0.104 0.110 2 toluene 0.067 3.6~9.6 8.1 0.012 0.019 0.114 4.8~16 9.2 0.037 0.044 0.504 3.0~9.0 1.8 0.089 0.093 3 ethylbenzene 0.012 15~19 12 0.006 0.007 0.056 13~18 8.4 0.024 0.026 0.404 4.2~13 3.7 0.100 0.100 4 p-xylene 0.012 15~20 13 0.005 0.007 0.058 10~19 7.0 0.026 0.027 0.383 12~18 4.2 0.154 0.161 5-xylene 0.012 9.5~19 11 0.006 0.006 0.055 11~19 6.6 0.023 0.024 0.385 12~20 3.4 0.165 0.174 6 cumene 0.010 9.7~19 12 0.004 0.005 0.056 6.4~17 4.1 0.021 0.021 0.374 9.5~20 4.7 0.141 0.144 7 o-xylene 0.011 13~20 9.0 0.005 0.006 0.055 14~18 9.3 0.024 0.027 0.372 8.3~19 2.3 0.132 0.141 8 n-propylbenzene 0.010 12~19 8.7 0.004 0.005 0.056 5.6~19 8.5 0.023 0.025 0.365 8.2~19 3.3 0.129 0.136 9 styrene 0.010 6.3~19 11 0.004 0.004 0.049 11~19 7.2 0.020 0.021 0.345 4.5~12 3.5 0.087 0.087

Table B.2 Accuracy of solid waste methods

Serial number

Compound

name

content

(mg/kg)

Addition recycling

Rate range (%)

Addition recycling

Rate average (%)

Standardized recovery rate standard deviation(%) Scaling recovery final value SP 2+/-/(%) 1 benzene 0.017 61.0~71.8 67.2 4.0 67.2±8.0 0.064 60.4~70.7 64.1 4.1 64.1±8.2 0.432 84.5~88.7 86.4 1.6 86.4±3.2 2 toluene 0.067 40.0~54.0 46.9 5.0 46.9±10 0.114 52.5~69.7 59.0 7.0 59.0±14 0.504 86.5~94.0 89.8 2.6 89.8±5.2 3 ethylbenzene 0.012 40.8~55.5 49.0 5.9 49.0±12 0.056 49.1~61.7 56.3 4.7 56.3±9.4 0.404 76.3~85.5 80.9 3.0 80.9±6.0 4 p-xylene 0.012 38.6~55.9 46.2 6.2 46.2±12 0.058 52.0~62.4 58.1 4.1 58.1±8.2 0.383 71.1~80.2 76.7 3.2 76.7±6.4 5-xylene 0.012 40.7~54.5 47.8 5.3 47.8±11 0.055 51.2~59.8 55.4 3.7 55.4±7.4 0.385 72.9~80.1 77.0 2.6 77.0±5.2 6 cumene 0.010 36.3~48.4 41.8 5.1 41.8±10 0.056 53.2~59.2 56.1 2.3 56.1±4.6 0.374 70.5~79.6 74.8 3.5 74.8±7.0 7 o-xylene 0.011 39.5~51.3 44.9 4.1 44.9±8.0 0.055 49.3~63.4 54.9 5.1 54.9±10 0.372 71.9~76.6 74.4 1.7 74.4±3.4 8 n-propylbenzene 0.010 35.9~43.3 39.4 3.4 39.4±6.8 0.056 50.8~63.8 56.4 4.8 56.4±9.6 0.365 69.5~75.1 73.0 2.4 73.0±4.8 9 styrene 0.010 34.8~46.8 39.1 4.3 39.1±8.6 0.049 42.3~52.5 49.1 3.5 49.1±7.0 0.345 65.7~71.1 68.9 2.4 68.9±4.8

Table B.3 Precision of the method of solid waste water leaching

Serial number

Compound

name

concentration

Experimental room relative standard deviation(%) Interlaboratory standard deviation(%) Repeatability limit r (µg/L) Reproducibility limit R (µg/L) 1 benzene 4.6 3.5~8.2 3.6 0.7 0.8 19.3 1.6~6.1 4.5 2.4 3.3 98.8 1.3~3.9 0.83 8.4 8.8 2 toluene 9 3.0~7.9 6.2 1 2 23 0.93~3.3 5.9 1 4 100 1.4~4.7 1.4 8 8 3 ethylbenzene 4.5 4.1~6.7 4.9 0.6 0.9 19.7 0.88~4.4 1.2 1.8 1.8 99.8 0.55~3.7 2.4 7.0 9.2 4 p-xylene 4.5 4.7~8.1 6.0 0.7 1.0 19.4 1.2~4.7 3.9 1.9 2.7 97.3 1.0~4.3 4.2 8.0 13.5 5-xylene 4.5 1.4~8.1 2.8 0.6 0.7 19.7 1.1~3.8 2.0 1.7 1.9 99.7 0.83~3.0 1.7 6.4 7.5 6 cumene 4.4 1.7~10 6.2 0.8 1.0 19.7 1.2~4.4 2.5 1.8 2.1 98.5 1.8~4.0 2.8 7.4 10.2 7 o-xylene 4 1.2~8.5 3.0 1 1 19 1.4~4.7 3.1 2 2 99 1.8~4.6 2.0 8 9 8 n-propylbenzene 5 1.4~7.1 4.0 1 1 20 1.4~5.0 2.0 2 2 99 1.1~3.5 0.78 8 8 9 styrene 4.4 1.2~14 3.1 0.9 0.9 20.0 0.76~5.2 1.5 2.3 2.3 98.6 0.53~4.4 1.6 8.6 9.1

Table B.4 Accuracy of the method of solid waste water leaching

Serial number

Compound

name

concentration

Spike recovery

range(%)

Spike recovery

Mean (%)

Standardized recovery rate standard deviation(%) Scaling recovery final value SP 2+/-/(%) 1 benzene 4.6 86.7~96.6 91.3 3.3 91.3±6.6 19.3 88.0~99.8 96.5 4.4 96.5±8.8 98.8 98.0~100 98.8 0.82 98.8±1.6 2 toluene 9 7...