HJ 703-2014Soil and sediment-Determination of phenolic compounds. (English PDF)

5.2 Column. 30 m × 0.25 mm × 0.25 µm, 100% methyl silicone capillary column; or 30 m × 0.25 mm

× 0.25 µm, 50% 50% phenyl methyl silicone capillary column, capillary column, or other equivalent.

5.3 Extraction equipment. Soxhlet extraction apparatus, the probe can also be used ultrasonic extractor, microwave or pressurized fluid extraction device Extracting means.

5.4 funnel. with polytetrafluoroethylene (PTFE) stoppers.

5.5 concentration device. a rotary evaporator means or KD concentrators, nitrogen blowing instrument, such as concentrated a considerable performance devices.

5.6 mortar. made of glass, agate or other non-interfering substance material.

5.7 micro syringe. 10 µl, 25 µl, 100 µl, 250 µl, 500 µl and 1000 µl.

5.8 General Commonly used laboratory instruments and equipment.

6.1 Sample Collection and preservation

Soil samples were collected in accordance with HJ/T relevant provisions of 166. According to GB 17378.3 and GB 17378.5 relevant Provisions collect sediment samples.

In brown glass bottles, should be analyzed as soon as possible after sample collection enclosed storage. If not timely analysis should be refrigerated from light, Retention period of 10 d. Avoid organic interference. Sample extract dark cold storage, shelf life 40 d.

6.2 Preparation of the sample

6.2.1 Dehydration

Removal of a sample of foreign objects (stones, blades, etc.), weigh about 10 g (accurate to 0.01 g) in duplicate samples, soil samples A product according to HJ 613 Determination of dry matter content, another adding an appropriate amount of anhydrous sodium sulfate (4.3), are milled into quicksand Like, such as using pressurized fluid extraction, then dehydrated with diatomaceous earth (4.15). A sediment sample measured in accordance with GB 17378.5 Fixed moisture content, another reference soil samples dehydration.

6.2.2 Extraction

Alternatively Soxhlet extraction, pressurized fluid extraction, ultrasonic extraction and microwave extraction any way desired compound extract.

6.2.2.1 Soxhlet

6.2.1 The sample was fully transferred to the paper sleeve (4.18), add 100 ml of methylene chloride and n-hexane mixed Co-solvent (4.11) and extracted 16 ~ 18 h, the reflux rate controlled at 10 times/h or so, after cooling to collect all extracts prepared Net of use.

6.2.2.2 Pressurized fluid extraction

According to a sample obtained 6.2.1 Volume Select the appropriate extraction cell, sample loading, methylene chloride and n-hexane mixed solvent Agent (4.11) as the extraction solvent, the following reference conditions for extraction. temperature of 100 °C, extraction pressure of 1500 psi, Static extraction time 5 min, elution volumes of 60% of the cell volume, nitrogen purge time 60 s, extraction cycles twice. and also You can refer to the instrument manufacturers instructions set conditions. The extract was collected, to be purified.

6.2.2.3 Ultrasonic extraction

6.2.1 sample volume obtained according to choose the right Erlenmeyer flask, add the amount of methylene chloride and n-hexane mixed solvent (4.11), making up at least a solid surface 2 cm, the ultrasound probe is placed below the liquid surface, the ultrasonic extraction 3 times 3 min, Control the extraction temperature does not exceed 40 °C (can be conical flask in an ice-water bath), the combined extracts were to be purified.

6.2.2.4 Microwave extraction

The sample was transferred to a microwave extraction 6.2.1 was special container, adding an appropriate amount of a mixed solvent of dichloromethane and hexane (4.11), the liquid level must not over-sample and less than 2/3 of the depth of the container (sample can be divided into multiple separate excessive extraction, and finally close and extract). Microwave extraction reference conditions. power 800 W, within 5 min to warm to 75 °C, maintained 10 min. Be extracted After cooling liquid filtration, mixed with the amount of solvent (4.11) and wash the container wall sample collected extract, to be purified.

6.2.3 Purification

6.2.2 The extract was transferred to a separatory funnel (5.4), and twice the volume of the aqueous extract with NaOH Solution (4.4) was adjusted to pH > 12, thoroughly shaken and allowed to stand, the lower organic phase was discarded, the aqueous phase retained portion.

NOTE. If the darker the organic phase may be appropriate to increase the number of times to purify the 2 or 3 times.

6.3 Extraction and concentration

6.2.3 The obtained portion was washed with aqueous hydrochloric acid solution (4.5) adjusted pH 7 Procedure

7.1 GC reference conditions

Inlet temperature. 260 °C; injection mode. split or not to split; injection volume. 1.0 µl. Oven temperature program.

80 °C held 1.0 min, at a heating rate of 10 °C/min and held raised to 250 °C 4.0 min; FID detector temperature.

280 °C. Within the column carrier gas flow rate. 1.0 ml/min; makeup. nitrogen, flow rate. 30 ml/min; flow rate of hydrogen. 35 ml/min;

Air flow rate. 300 ml/min.

7.2 Calibration

Exact Pipette stock standard solution (4.12) 5.0µl, 25.0µl, 100µl, 250µl and 500µl in 5 ml flask, Mixed with methylene chloride and ethyl acetate solvent (4.10) diluted to the mark, the preparation of the calibration series, the concentration of the target compound, respectively of 1.00 mg/L, 5.00 mg/L, 20.0 mg/L, 50.0 mg/L and 100 mg/L. Instrument under recommended conditions (7.1) into Line measurements to the concentration of each component as abscissa, to the component peak area (or height) as ordinate plotted calibration curve.

7.3 Reference chromatogram

According to gas chromatography reference conditions (7.1) analysis, 21 kinds of phenolic compounds in 100% methyl polysiloxane (non-polar) Reference chromatogram column on Figure 1.

Elution order. 1 - Phenol, 2- 2-chlorophenol, 3-o - cresol, 4/5-p/m - cresol, 6-2- nitrophenol, 7-2,4-di-p-cresol , 8- 2,4-dichlorophenol, 2,6-dichlorophenol 9-, 10- 4-chloro-m-cresol, 11-2,4,6- trichlorophenol, 12-2,4,5 - trichlorophenol, 13-2,4-Dinitrophenol, 14-4- nitrophenol, 15-2,3,4,6- tetrachlorophenol, 16/17- 2,3,4,5-chlorophenol/2,3,5,6 - four chlorophenol, methyl-4,6-18-2-Dinitrophenol, 19- pentachlorophenol, 20-2- (1-methyl - n-propyl) -4,6-dinitrophenol (dinoseb), 21-2- cyclohexyl-4,6 dinitrophenol

Figure 121 phenols reference chromatogram

7.4 Determination

The prepared sample (6.3) in accordance with the GC reference conditions (7.1) were measured.

7.5 Blank test

Weigh 10.0 g of quartz sand (4.14), according to the sample preparation step from 6.2 to 6.3, according to gas chromatography reference conditions (7.1) Determination.

8 represents the results of calculation and

8.1 Qualitative target compound

Sample analysis should be established retention time windows t ± 3S. t when the initial concentration of each standard calibration material retention time Average initial calibration when S is the standard deviation of each standard retention time. When the sample analysis, the target compound with a retention Retention time should be within the time window. Target compound analysis column retention time (non-polar) on Appendix B.

8.2 Calculation Results

The target compound with external standard, the content of phenolic compounds in soil (mg/kg) according to formula (1) is calculated, 2.5 5.0 7.5 10.0 12.5 15.0 17.5 min 0.00 0.25 0.50 0.75 1.00 1.25 twenty one Sediment content of phenolic compounds (mg/kg) according to the formula (2) is calculated.

i wm

× = rhoomega (1)

Wherein. the content of the target compound omegai-- sample, mg/kg;

rhoi-- calculate the mass concentration of the resulting target compound, mg/L by the calibration curve;

V-- constant volume sample volume, ml;

Quality m-- soil sample (wet weight), g;

Soil samples wdm-- dry matter content,%.

) 1 (wm

× = rhoomega (2)

Wherein. the content of the target compound omegai-- sample, mg/kg;

rhoi-- calculate the mass concentration of the resulting target compound, mg/L by the calibration curve;

V-- constant volume sample volume, ml;

Quality m-- sediment sample (wet weight), g;

w-- sediment sample moisture content,%.

8.3 The results are shown

8.3.1 When the result is greater than equal to 1.00 mg/kg, the result of three significant figures; less than 1.00 mg/kg, the result Reserved to two decimal places.

8.3.2 Inter - cresol and p - cresol, 2,3,4,5-chlorophenol and 2,3,5,6-chlorophenol difficult separation of substances on the measurement results difficult Separation of substances and for the two.

9.1 Precision

Six laboratories of the target compound concentration of about 0.05 mg/kg, 0.65 mg/kg ~ 3.63 mg/kg and 2.58 mg/kg ~ 6.46 mg/kg of unified samples were measured in the laboratory relative standard deviation of 3.8% ~ 40.7%, 24.4% and 1.6% 2.1% 20.4%; interlaboratory relative standard deviation of 8.9% ~ 30.7%, 56.0% and 13.3% ~ 22.2% ~ 41.6%;

Reproducible range limit. 0.01 mg/kg ~ 0.05 mg/kg, 0.14 mg/kg ~ 1.03mg/kg and 0.48 mg/kg ~ 1.40 mg/kg; reproducibility range limit. 0.02 mg/kg ~ 0.08 mg/kg, 0.42 mg/kg ~ 5.72 mg/kg and 1.81 mg/kg ~ 7.58 mg/kg.

9.2 Accuracy

Six laboratories actual sediment samples of two different concentrations of matrix spiked sample measured, the amount of matrix spiked 1.00 mg/kg and 4.00 mg/kg, the recoveries range of the target compound. 59.1% ~ 89.2% and 61.8% ~ 95.9%.

Specific method precision and accuracy of the data provided in Appendix C.

10.1 Calibration curve

Linear calibration curve fitting, and the correlation coefficient should be greater than or equal 0.995, or need to re-draw the calibration curve.

10.2 Calibration Verification

Each analysis should select the calibration curve calibration curve for an intermediate concentration of the sample prior to verification, the measurement results relative deviation should <=30%, otherwise it should be re-calibration curve.

10.3 Blank

Each batch of samples to be simultaneously a blank test. Blank results should be less than the target compound concentration detection limit.

Parallel sample measured 10.4 each batch of samples (up to 20 samples) shall be measured at least once parallel, twin-like measurement results relative deviation should Less than 30%.

10.5 Actual spiked and spiked parallel

Each batch of samples (up to 20 samples) should be analyzed at least one actual samples spiked with a spiked parallel. The actual sample Product recoveries should be between 50% to 140% and the parallel sample measurement results relative deviation should be less than 30%.

If the recovery rate below standard, and spiked in parallel to meet the requirements, indicating the presence of the sample matrix effects, note in results Bright.

12.1 Calibration curve range

Calibration curve concentration range may be suitably adjusted according to the actual sample concentration. Low concentration profile available standard solution (4.13) Formulated.

12.2 Actual samples

For samples exceeding the upper limit of the target compound of the calibration curve can be diluted or reduce the amount of re-sampling analysis.

The instrument will sample containing a high concentration of phenolic compounds memory effect, should then analyze one or more blank Product until after the results of blank test meet the quality control requirements in order to analyze the next sample.

When necessary, can be 30 m × 0.25 mm × 0.25 µm, 50% to 50% phenyl methyl polysiloxane (medium polarity) capillary Do the qualitative secondary confirmation column, mass spectrometry can also be used for further confirmation. Qualitative auxiliary column chromatography reference conditions see 7.1, color Spectrum See Appendix D.

Appendix A

(Normative)

The detection limit and lower limit of determination

Table A detection limit and lower limit of determination

No. Ingredient name detection limit (mg/kg) detection limit (mg/kg) 1 phenol 0.04 0.16 22- chlorophenol 0.04 0.16 3 o - cresol 0.02 0.08 4/5 p/m - cresol 0.02 0.08 62- nitrophenol 0.02 0.08 7 2,4-cresol 0.02 0.08 8 0.03 0.12 2,4-dichlorophenol 2,6-dichlorophenol 0.03 9 0.12 104--chloro-3-cresol 0.02 0.08 11 2,4,6-trichlorophenol 0.03 0.12 12 2,4,5-trichlorophenol 0.03 0.12 13 2,4-dinitrophenol 0.08 0.32 144- nitrophenol 0.04 0.16 15 0.02 0.08 2,3,4,6-tetra-chlorophenol 16/17 2,3,4,5-chlorophenol/2,3,5,6-chlorophenol 0.03 0.12 182- methyl-4,6-dinitrophenol 0.03 0.12 PCP 19 0.07 0.28 2- (1-methyl - n-propyl) -4,6-dinitrophenol (Dinoseb) 0.02 0.08 212- cyclohexane-4,6-dinitrophenol 0.02 0.08 Appendix B (Informative) Retention time of the target compound and reference

Table B phenolic compounds on a non-polar column reference retention time

No. Ingredient name English name keep time* (Min)

1 Phenol Phenol 4.76 22- Chlorophenol 2-Chlorophenol 5.05 3 o - cresol 2-Methylphenol 5.70 4/5 p/m - cresol 4-Methylphenol/3-Methylphenol 6.05 62- nitrophenol 2-Nitrophenol 6.80 7 2,4-cresol 2,4-Dimethylphenol 6.99 8 2,4-dichlorophenol 2,4-Dichlorophenol 7.38 9 2,6-dichlorophenol 2,6-Dichlorophenol 7.82 104--chloro-3-cresol 4-Chloro-3-methylphenol 8.89 11 2,4,6-trichlorophenol 2,4,6-Trichlorophenol 9.89 12 2,4,5-trichlorophenol 2,4,5-Trichlorophenol 9.98 13 2,4-dinitrophenol 2,4-Dinitrophenol 11.43 144- Nitrophenol 4-Nitrophenol 11.82 15 2,3,4,6-tetra-chlorophenol 2,3,4,6-Tetrachlorophenol 12.05 16/17 2,3,4,5-chlorophenol/2,3,5,6-chlorophenol 2,3,4,5-Tetrachlorophenol/2,3,5,6-Tetra 12.52 182- methyl-4,6-dinitrophenol, 2-Methyl-4,6-dinitrophenol 13.03