Solid waste leachate—Determination of Chlordane—Gas Chromatography (1)

1.

This method is suitable for the determination of γ-chlordane and α-chlordane content in solid waste leachate

Second, the principle of the method

Chlordane in the extract was extracted with dichloromethane , and the extract was dehydrated, dried, concentrated, purified, changed solvent, and fixed to volume with anhydrous sodium sulfate, and then separated and separated by a gas chromatograph with an electron capture detector (ECD).

3.

(1) Ultra-pure water: No experimental interference, can be purchased or prepared in the laboratory

(2) Dichloromethane : pesticide residue level

(3) N-hexane : pesticide residue level

(4) Anhydrous sodium sulfate : pure superior grade

(5) Sodium chloride: pure superior grade

(6) Concentrated sulfuric acid : pure superior grade

(7) Concentrated nitric acid : pure superior grade

(8) Extractant: Add a mixture of concentrated sulfuric acid and concentrated nitric acid with a mass ratio of 2:1 to ultrapure water (approximately 2 drops of 1L water) to make the pH 3.

(9) Standard solution γ-Chlordane: ρ=100ug/mL; α-Chlordane: ρ=200ug/mL

Four, instruments and equipment

(1) Gas chromatograph: with electron capture detector (ECD)

(2) Chromatographic column:

Front column: HP-17 (30m×0.

Back column: HP-5 (30m×0.

(3) Concentration device: equipment with equivalent performance such as nitrogen blowing concentrator and rotary evaporator
.

(4) Extraction bottle: 2L PTFE jar with screw cap and inner cap
.

(5) Separation funnel: 250mL
.

(6) Flip-type oscillating device
.

Five, pre-treatment

(1) Preparation of solid waste leachate

"Semi-Volatile Organic Compound Analysis Technology-Preparation of Sulfuric Acid and Nitric Acid from Leachate"

(2) Extraction

Take 100 mL of the solid waste extract in a separatory funnel, add an appropriate amount of sodium chloride and 15 mL of dichloromethane to fully shake, shake, and stand still, remove water through a funnel with an appropriate amount of anhydrous sodium sulfate , and collect the organic phase
.
The extraction was repeated twice as described above, the sodium sulfate was washed thoroughly with dichloromethane , and the organic phases were combined and collected in a pear-shaped flask for concentration
.

(3) Concentration and purification

(1) Concentration: When using a rotary evaporator to concentrate, the temperature of the water bath is 30°C
.
Concentrate to 4mL, add 4mL of n-hexane, continue to concentrate to 1.
0mL for GC-ECD determination
.

(2) Purification: If the color of the extract is dark, it needs to be purified by sulfuric acid before it can be analyzed on the computer
.

Related Links: Solid Waste Leachate—Determination of Organochlorine Pesticides—Gas Chromatography (2)