Soil and sediment. Determination of acrolein, acrylonitrile and acetonitrile. Gas chromatography (2)

Six, analysis and testing

(1) Instrument conditions (for reference only, can be adjusted appropriately according to the actual instrument)

1.

Heating equilibration temperature: 90℃, sampling system temperature: 90℃, transfer line temperature: 130℃, equilibration time: 15min, sample interrogation interval 26min

2.

The temperature of the sampling plant is 150℃, and the sampling method: split injection, the split ratio is 1:1, constant pressure control, and the injection volume is 1.

Detector: FID, temperature: 250°C, hydrogen: 40 mL/min, air: 400 mL/min, makeup: 30 mL/min

(2) Calibration curve

Weigh 2g of quartz sand into the headspace bottle, quickly add 10mL matrix modifier, add a certain amount of standard solution, and prepare a standard series of more than 5 points (such as 2.

The retention time qualitative and quantitative ions under the reference instrument conditions are shown in Table 8-5

Table 8-5 Retention time

7.

Determination of Volatile Aromatic Hydrocarbons in Soils and Sediments Gas Chromatography (2) -Calculation of Results

8.

(1) Calibration curve

Use the linear fitting curve to calibrate, the correlation coefficient should not be less than 0.

(2) Blank analysis

Each batch of samples (up to 10 samples) should be a laboratory blank, and the mass concentration of the target compound in the blank result should be less than the detection limit of the method

(3) Determination of parallel samples

Each batch of samples (up to 10 samples) should be tested in parallel once, and the relative deviation of the results of parallel samples should be within 20%

(4) Determination of the actual sample spike

Each batch of samples (up to 10 samples) should be spiked with actual samples at least once, and the spike recovery rate should be between 80% and 120%

Nine, matters needing attention

(1) The reagents and standard solutions used in the experiment are toxic reagents.

(2) Sodium chloride and quartz sand should be burned in a muffle furnace at 450°C for 4 hours to remove other impurities before use
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(3) Before getting on the machine, make sure whether the headspace bottle cap is completely sealed, otherwise it will cause deviation of the result
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(4) All tools used in this experiment, such as medicine spoons, are recommended to be washed and dried with methanol before being used
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Related Links: Determination of Acrolein, Acrylonitrile and Acetonitrile in Soils and Sediments by Gas Chromatography (1)