Soil and sediment determination of polychlorinated biphenyls gas chromatography-mass spectrometry (1)

1.

This method is suitable for the determination of 18 kinds of PCBs in soil and sediment .

After the applicability of other PCB compounds has been verified, this method can also be used for analysis

Second, the principle of the method

Use pressurized fluid extraction method to extract PCBs in soil or sediments, and select appropriate purification methods (concentrated sulfuric acid sulfonation, copper powder desulfurization, Flori silica column, silica gel column, etc.

3.

Unless otherwise stated, the analysis is performed with superior grade pure chemical reagents that meet the national standards, and the experimental water is newly prepared ultrapure water

(1) N-hexane : pesticide residue level

(2) Methanol : pesticide residue level

(3) Acetone : pesticide residue level

(4) Toluene : pesticide residue level

(5) Sodium chloride : Heat at 450°C for 4 hours, cool to room temperature in a desiccator, seal and store in a clean reagent bottle

(6) Anhydrous sodium sulfate : Heat at 450°C for 4 hours, cool to room temperature in a desiccator, seal and store in a clean reagent bottle

(7) Sulfuric acid : p(H2SO4)=1.

(8) Sodium chloride solution: p(NaCl)=0.

(9) Eluent: acetone-n-hexane mixed solution with a volume ratio of 1:9

(10) Standard stock solution: p=10.

(11) Internal standard: PCB77-d6, PCB156-2',6,6'-d3, p=10.
0ug/mL, the solvent is n-hexane
.

(12) Substitutes: PCB28-2', 3', 5', 6'-d4, PCB114-2', 3', 5', 6'-d4, p=10.
0ug/mL, the solution is n-hexane
.

(13) decafluoro triphenylphosphonium : p = 10ug / mL, the solvent is n-hexane
.

(14) Flori silica solid phase column: 1000mg, 6mL
.

(15) Silica gel column: 1000mg, 6mL
.

(16) Graphite carbon column: 1000mg, 6mL
.

(17) Copper sheet: Use dilute hydrochloric acid solution to remove the oxides on the surface of the copper powder before use, rinse with experimental water to remove the acid, and rinse with acetone , then dry it with nitrogen until it is used.
Treat each time before use to keep the surface of the copper sheet Bright
.

(18) Quartz sand: 40-100 mesh, heated at 450°C for 4 hours, placed in a desiccator to cool to room temperature, sealed and stored in a clean reagent bottle
.

(19) Diatomaceous earth: 60 mesh, heated at 450°C for 4 hours, placed in a desiccator to cool to room temperature, sealed and stored in a clean reagent bottle
.

Four, instruments and equipment

(1) EI source single quadrupole gas chromatography mass spectrometer
.

(2) Chromatographic column: HP-5MSUI, 30m×0.
25mm×0.
25um
.

(3) Pressurized fluid extraction device
.

(4) Centrifugal glass tube: 22mL, 40mL
.

(5) Balance: the accuracy is 0.
01g
.

(6) Oven
.

Related Links: Determination of Polycyclic Aromatic Hydrocarbons in Soils and Sediments Gas Chromatography-Mass Spectrometry (3)