1.Method: Gas Chromatography

• Apparatus: Gas chromatograph equipped with a FID detector.
• Column: Glass, 42cm¡Á2mm(id), loaded with Gas Chrom Q (100-120#)
• Condition:

Temperature of inlet: 160-170¡æ

Detector temperature: 160¡æ

Oven temperature: 156¡À2¡æ

Carrier gas: N2

Flow rate(ml/min): N2: 28; H2: 35; Air: 600

Injection: 0.2-0.4¦ÌL

Acephate retention time: c. 8min.

Decanedinitrile retention time: c. 5min.

• Solution preparation:

(1) Internal standard preparation: Weigh decanedinitrile c. 0.12g (accurate to 0.0002g), to 50ml volumetric flask, dilute to scale with chloroform and mix well. Sealed storage in 5¡æ icebox.

(2) Standard preparation: Weigh 0.08g(accurate to 0.0002g) acephate standard sample, add to 10ml volumetric flask, put into 5ml internal standard solution with pipette and mix well.

(3) Test preparation: Weigh 0.08g(accurate to 0.0002g) acephate test sample, add to a flask with stopple, put into 5ml internal standard solution with pipette and mix well.

5.Test: Under the operation conditions specified above, inject several times of the standard solution until the baseline is stable. When the peak area of acephate varies by less than 2.0% for successive injection, then carry on the determination according to the order: standard solution, sample solution, sample solution, standard solution.

6.Calculation:

Where, R1: the average peak area ratio of acephate and internal standard material in standard solution.

R2: the average peak area ratio of acephate and internal standard material in sample solution.

m1: mass of acephate standard sample, g

m2: mass of acephate test sample, g

P: purity of acephate standard sample, %

7. Tolerance: