HJ 997-2018Soil and sediment - Determination of carbonyl compounds - High performance liquid chromatography (English PDF)

6.1 Sample collection and preservation

Soil samples were collected and stored in accordance with the relevant regulations of HJ/T 166. Water according to the relevant regulations of HJ 494 Collection of bulk sediment samples. The collection of marine sediment samples is carried out in accordance with the relevant provisions of GB 17378.3.

Use a shovel or stainless steel scoop to collect the sample into the vial (5.3) as soon as possible and fill it up. Quickly remove the sample vial the sample adhered to the grain and the outer surface, sealed the sample bottle, and stored in the dark. If not analyzed in time, refrigerate below 4 ° C, 5 d Derivatization and extraction were completed, and the derivatized extract was analyzed within 7 days.

6.2 Preparation of samples

Remove foreign matter (stones, leaves, etc.) from the sample and weigh 10 g (accurate to 0.01 g) of the sample in the extraction bottle (5.11) in. Another sample was weighed to determine the dry matter content or moisture content.

6.3 Determination of moisture

The dry matter content of the soil sample was measured according to HJ 613, and the moisture content of the sediment sample was determined in accordance with GB 17378.5.

6.4 Preparation of samples

6.4.1 Extraction

In the extraction vial containing the sample (6.2), add.200 ml of extractant (4.11), sealed, in the shaker (5.4) the mixture was shaken for not less than 18 h, filtered through a glass fiber filter (4.18), and the extract was collected for derivatization.

6.4.2 Derivative

Take 100 ml of extract (6.4.1) in a flat-bottomed flask (5.12), add 4 ml of buffer solution (4.12), 6 ml the biocide (4.13) was placed in a constant temperature oscillator (5.5) and shaken at 40 ° C for 1 h.

Note. You can use a temperature-controlled ultrasonic cleaner or ultrasonic extractor instead of a constant temperature oscillator. The ultrasonic time is not less than 30 min, and the ultrasonic temperature is not exceeded.

Over 40 ° C ± 2 ° C.

46.4.3 Extraction and concentration

6.4.3.1 Solid phase extraction the solid phase extraction column (5.9) was fixed on a solid phase extraction apparatus (5.6) with 10 ml of acetonitrile (4.8) and 10 ml, respectively.

Water activated extraction column. Add 10 ml of sodium chloride solution (4.10) to the derivatized solution (6.4.2) and transfer to the extraction column.

The loading speed is 3 ml/min~5 ml/min. Rinse the vessel and tubing with 10 ml of water and continue to pump for 1 min. use 9 ml of acetonitrile (4.8) was eluted from the extraction column at a flow rate of 3 ml/min to 5 ml/min, and the eluate was collected into a 10 ml volumetric flask.

Dilute to the mark with acetonitrile (4.8), mix and test.

6.4.3.2 Liquid-liquid extraction Transfer the derivatized solution (6.4.2) to a separatory funnel (5.10) and add 1.5 g of NaCl (4.1), respectively.

15 ml and 10 ml of dichloromethane (4.9) were extracted twice, and the extracts were combined and the extract was dehydrated with anhydrous sodium sulfate (4.2).

Concentrate to near dryness with a concentration device (5.7), change the solvent to acetonitrile (4.8), determine the volume to 10 ml with acetonitrile, and mix.

To be tested.

Note. High concentration samples can be appropriately added once.

6.5 Preparation of blank samples the sample was replaced with quartz sand (4.17), and the preparation of the blank sample was carried out in the same manner as in the preparation of the sample (6.4).

7 Analysis steps

7.1 Reference chromatographic conditions Mobile phase. 60% acetonitrile 40% water, isocratic elution, hold for 30 min;

Detection wavelength. 360 nm;

Mobile phase flow rate. 1.0 ml/min;

Column temperature. 30 ° C;

Injection volume. 10 µl.

7.2 Establishment of the standard curve Transfer an appropriate amount of aldehyde, ketone-DNPH standard solution (4.14), and make a mass concentration of 0.03 with acetonitrile (4.8).

Standard series of mg/L, 0.05 mg/L, 0.10 mg/L, 0.50 mg/L, 1.00 mg/L and 1.50 mg/L. According to reference color Spectral conditions (7.1) were determined by taking the standard series target compound concentration as the abscissa and its corresponding peak area or peak height.

For the ordinate, a standard curve is established.

7.3 Reference chromatogram the chromatograms of the 15 aldehyde and ketone anthracene derivatives on the C18 column (5.2) are shown in Figure 1.

Note. See Appendix B for the separation of other different types of columns.

51. Formaldehyde-DNPH; 2. Acetaldehyde-DNPH; 3. Acrolein-DNPH; 4. Acetone-DNPH; 5. Propionaldehyde-DNPH; 6. Butenal-DNPH; 7. Butyraldehyde-DNPH;

8. benzaldehyde-DNPH; 9. isovaleraldehyde-DNPH; 10. n-pentanal-DNPH; 11. o-methylbenzaldehyde-DNPH; 12. m-methylbenzaldehyde-DNPH;

13. p-Methyl benzaldehyde-DNPH; 14. n-hexanal-DNPH; 15.2,5-dimethylbenzaldehyde-DNPH.

Figure 1 Reference chromatogram of 15 aldehyde and ketone anthracene derivatives

7.4 Sample determination the measurement of the sample (6.4) was carried out in the same manner as the establishment of the standard curve (7.2).

7.5 Blank test

The blank sample (6.5) was measured in the same manner as in the sample measurement (7.4).

8 Calculation and representation of results

8.1 Qualitative analysis Qualitative according to the retention time of the target compound. If necessary, use standard addition method, absorption ratio at different wavelengths, UV Methods such as spectral scanning aid the qualitative.

8.2 Calculation of results

8.2.1 Calculation of results of soil samples the target content w in the soil sample is calculated according to formula (1).

2dm

V Vw m WV

x x= x x (1)

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

--the mass concentration of the target compound in the sample calculated from the standard curve, mg/L;

V--sample volumetric volume, ml;

V1--extractant volume, ml;

V2--extraction sample volume, ml;

m -- sample weighing, g;

dmW - sample dry matter content, %.

68.2.2 Calculation of results of sediment samples

The target content w in the sediment sample is calculated according to formula (2).

twenty one-

V Vw m WV

x x= x x ( ) (2)

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

--the mass concentration of the target compound in the sample calculated from the standard curve, mg/L;

V--sample volumetric volume, ml;

V1--extractant volume, ml;

V2--extraction sample volume, ml;

m -- sample weighing, g;

W--sample moisture content, %.

8.3 Result representation the retention of the number of digits after the decimal point is consistent with the method detection limit, and up to 3 significant digits are retained.

Note. m-methylbenzaldehyde-DNPH and p-methylbenzaldehyde-DNPH are difficult to separate substances. When the column cannot separate the two, measure the result is the sum of the difficult to separate substances.

9 Precision and accuracy 9.1 precision Six laboratories added aldehyde and ketone compounds to soils with concentrations of 0.20 mg/kg, 0.50 mg/kg, and 2.00 mg/kg, respectively.

The soil samples were subjected to 6 repeated measurements, and the relative standard deviations in the laboratory were 4.8% to 29% and 4.3% to 33%, respectively.

0.20%~29%; the relative standard deviations between laboratories are. 10%~20%, 6.4%~20%, 6.6%~20%; repeatability limit Respectively. 0.05 mg/kg to 0.09 mg/kg, 0.14 mg/kg to 0.22 mg/kg, 0.37 mg/kg to 0.72 mg/kg; reproducibility the limits are. 0.07 mg/kg ~ 0.10 mg/kg, 0.18 mg/kg ~ 0.25 mg/kg, and 0.66 mg/kg ~ 0.90 mg/kg.

Six laboratories added aldehydes and ketones at concentrations of 0.20 mg/kg, 0.50 mg/kg, and 2.00 mg/kg, respectively.

The samples were re-measured 6 times. The relative standard deviations in the laboratory were 2.8%~32% and 2.5%~29%, respectively.

1.7%~22%; the relative standard deviations between laboratories are. 7.9%~21%, 11%~19%, 6.7%~21%; repeatability limit Respectively. 0.05mg/kg ~0.09mg/kg, 0.10 mg/kg ~0.25 mg/kg, 0.33 mg/kg ~0.65 mg/kg; reproducibility the limits are. 0.07mg/kg ~0.11 mg/kg, 0.15 mg/kg ~0.38 mg/kg, 0.47 mg/kg ~1.02 mg/kg.

See Appendix C for precision results.

9.2 Accuracy

The concentration of aldehydes and ketones in the six laboratories was 0.20 mg/kg, 0.50 mg/kg, 2.00 mg/kg, respectively.

The soil samples were tested six times. The recoveries ranged from 43.5% to 101% and 41.5% to 99.0%.

42.0%~104%, the final recoveries of the spiked recovery are. 56.3%±19.0%~87.0%±20.4%, 51.2% ± 21.4% ~ 77.2% ± 35.2%, 50.8% ± 26.6% ~ 88.7% ± 14.8%.

The concentration of aldehydes and ketones in the six laboratories was 0.20 mg/kg, 0.50 mg/kg, 2.00 mg/kg, respectively.

7 Sediment samples were subjected to 6 replicate measurements. The recoveries ranged from 46.3% to 112% and 40.8% to 112%, respectively.

41.3%~116%, the final recoveries of the spiked recovery were. 54.5%±15.4%~91.2%±30.4%, 47.9%±22.8%~90.5%±26.2%, 45.2%±20.6%~94.7%±32.0%.

See Appendix C for accuracy results.

10 Quality Assurance and Quality Control

10.1 At least one laboratory blank shall be analyzed for each batch of samples, and the target determination results shall be lower than the method detection limit.

10.2 The correlation curve of the standard curve should be >=0.999, otherwise it should be recalibrated.

10.3 Analyze at least 1 standard curve intermediate concentration point for every 20 samples or batches (less than 20 samples/batch) the relative error between the measured value and the standard value is within ±20%, otherwise the standard curve should be redrawn.

10.4 Test at least 1 parallel sample for every 20 samples or batches (less than 20 samples/batch), parallel sample determination results the relative deviation should be <= 45%.

10.5 Analyze at least 1 matrix plus standard for every 20 samples or batches (less than 20 samples/batch), aldehyde compounds the recovery should be between 45% and 120%, and the acetone recovery should be between 40% and 100%.

11 Waste treatment

The waste generated in the experiment should be collected and stored in a centralized manner and sent to a qualified unit for unified disposal.

12 Precautions

12.1 Washed glassware should be baked at 130 ° C for 2 h ~ 3 h before use.

12.2 Do not wash glassware with acetone, methanol or ethanol to avoid interference with the measurement.

12.3 When DNPH contains a target, it needs to be purified. See Appendix D for the purification method.

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 the target.

Table A.1 Method detection limits and lower limit of measurement

Serial number component name English name chemical registration number the detection limit (mg/kg) Lower limit of measurement (mg/kg)

1 Formaldehyde Formaldehyde 50-00-0 0.02 0.08

2 Acetaldehyde Acetaldehyde 75-07-0 0.04 0.16

3 Acrolein Acrolein 107-02-8 0.04 0.16 4 acetone Actone 67-64-1 0.04 0.16

5 Propional Propanal (Propionaldehyde) 123-38-6 0.04 0.16 6 crotonaldehyde Crotonaldehyde 123-73-9 0.04 0.16

7 Butanal Butanal (Butyraldehyde) 123-72-8 0.04 0.16 8 benzaldehyde Benzaldehyde 100-52-7 0.06 0.24 9 isovaleraldehyde Isovaleraldehyde 590-86-3 0.06 0.24 10 n-valeraldehyde Pentanal (Valeraldehyde) 110-62-3 0.06 0.24 11 o-methylbenzaldehyde o-Tolualdehyde 529-20-4 0.05 0.20 12-methylbenzaldehyde m-Tolualdehyde 620-23-5 0.06 0.24 13-methylbenzaldehyde p-Tolualdehyde 104-87-0 0.06 0.24

14 Hexanal (Hexaldehyde) 66-25-1 0.06 0.24 15 2,5-Dimethylbenzaldehyde 2,5-Dimethylbenzaldehyde 5779-94-2 0.06 0.24

9 Appendix B

(informative appendix) Reference chromatogram of 15 aldehyde and ketone anthracene derivatives Figures B.1~B.2 show the reference chromatograms of the different columns under the corresponding chromatographic separation conditions.

Column 1. The filler is a hydrophilic alkyl bonded porous silica gel with a particle size of 5.0 µm, a column length of 250 mm and an internal diameter of 4.6 mm.

Mobile phase. acetonitrile/water. Flow rate 1.5 ml/min, gradient elution, 60% acetonitrile for 8 min, 8 min~18 min Acetonitrile increased linearly from 60% to 70%, and acetonitrile increased linearly from 70% to 80% in 18 min~25 min, within 25 min~26 min the acetonitrile was linearly reduced from 80% to 60% for 5 min.

1. Formaldehyde-DNPH; 2. Acetaldehyde-DNPH; 3. Acrolein-DNPH; 4. Acetone-DNPH; 5. Propionaldehyde-DNPH; 6. Butenal-DNPH; 7. Butyraldehyde-DNPH;

8. benzaldehyde-DNPH; 9. isovaleraldehyde-DNPH; 10. n-pentanal-DNPH; 11. o-methylbenzaldehyde-DNPH; 12. m-methylbenzaldehyde-DNPH;

13. p-Methyl benzaldehyde-DNPH; 14. n-hexanal-DNPH; 15.2,5-dimethylbenzaldehyde-DNPH.

Figure B.1 Column 1 Reference Chromatogram

Column 2. The packing is octadecylsilane bonded porous silica gel with a particle size of 5.0 µm, a column length of 250 mm and an internal diameter of 4.6 mm.

Mobile phase. acetonitrile/water. Flow rate 1.5 ml/min, gradient elution, 60% acetonitrile for 8 min, 8 min~18 min Acetonitrile increased linearly from 60% to 70%, and acetonitrile increased linearly from 70% to 80% in 18 min~25 min, within 25 min~26 min the acetonitrile was linearly reduced from 80% to 60% for 5 min.

1. Formaldehyde-DNPH; 2. Acetaldehyde-DNPH; 3. Acrolein-DNPH; 4. Acetone-DNPH; 5. Propionaldehyde-DNPH; 6. Butenal-DNPH; 7. Butyraldehyde-DNPH;

8. benzaldehyde-DNPH; 9. isovaleraldehyde-DNPH; 10. n-pentanal-DNPH; 11. o-methylbenzaldehyde-DNPH; 12. m-methylbenzaldehyde-DNPH;

13. p-Methyl benzaldehyde-DNPH; 14. n-hexanal-DNPH; 15.2,5-dimethylbenzaldehyde-DNPH.

Figure B.2 Column 2 Reference Chromatogram

Appendix C

(informative appendix) Method precision and accuracy Tables C.1 and C.2 give the precision and accuracy indicators for the method's repeatability limits, reproducibility limits, and spike recovery.

Table C.1 Precision of the method

Compound name

sample

Types of

Standard concentration (mg/kg) Mean (mg/kg) Laboratory room Relative standard deviation(%) Laboratory room Relative standard deviation(%) Repeatability limit r (mg/kg) Reproducibility limit R (mg/kg) 1 formaldehyde soil 0.20 0.17 5.9~25 10 0.09 0.10 0.50 0.43 4.8~28 8.4 0.19 0.20 2.00 1.78 0.20~29 6.6 0.57 0.86 Sediment 0.20 0.17 6.2~27 11 0.09 0.10 0.50 0.45 5.8~24 12 0.25 0.27 2.00 1.90 3.1~12 12 0.37 0.69 2 acetaldehyde soil 0.20 0.16 5.5~24 18 0.08 0.09 0.50 0.38 5.0~26 10 0.17 0.18 2.00 1.56 5.1~29 8.5 0.63 0.68 Sediment 0.20 0.17 8.8~29 17 0.09 0.11 0.50 0.42 6.5~22 12 0.17 0.21 2.00 1.83 4.2~12 12 0.43 0.71 3 acrolein soil 0.20 0.13 9.6~22 15 0.06 0.08 0.50 0.34 7.1~26 14 0.14 0.19 2.00 1.41 4.3~26 18 0.71 0.89 Sediment 0.20 0.15 7.4~29 7.9 0.08 0.10 0.50 0.33 5.4~18 12 0.12 0.15 2.00 1.45 1.7~22 14 0.65 0.70 4 acetone soil 0.20 0.12 7.0~28 13 0.05 0.07 0.50 0.26 8.5~27 16 0.15 0.18 2.00 1.02 2.3~24 20 0.37 0.66 Sediment 0.20 0.11 4.4~32 11 0.06 0.07 0.50 0.24 2.5~23 17 0.13 0.16 2.00 0.91 4.7~16 17 0.33 0.53 5 propionaldehyde soil 0.20 0.14 6.3~23 12 0.06 0.07 0.50 0.37 6.8~31 6.4 0.22 0.21 2.00 1.62 5.2~27 7.1 0.72 0.72 Sediment 0.20 0.17 4.6~13 12 0.05 0.07 0.50 0.41 3.5~29 12 0.19 0.22 Compound name sample Types of Standard concentration (mg/kg) Mean (mg/kg) Laboratory room Relative standard deviation(%) Laboratory room Relative standard deviation(%) Repeatability limit r (mg/kg) Reproducibility limit R (mg/kg) 2.00 1.89 1.7~12 ...