A method was developed for the determination of cyanogen and hydrogen cyanide residues of fumigant in soil using gas chromatography with purge and trap. The working parameters were optimized using spiked lab blank samples. The results showed that the optimum conditions were found to be as follows: purge time; 60 min, purge temperature: 80 t, purge velocity of carrier gas(N2) : 40 mL Min-1 and 10% sulfuric acid as acidifying reagent. The calibration curves were linear over 0. 2 -10 mg L-1 of cyanogen and hydrogen cyanide with correlation coefficients of 0. 999 1 and 0. 998 3, respectively. Under the optimal conditions, the average recoveries of spiked cyanogen and hydrogen cyanide were 95% and 96% , respectively, with RSDs (re =6) of 3.6% and 5. 2% , respectively. The limits of detection (LOD, S/N = 3) of cyanogen and hydrogen cyanide were 0.012 and 0. 021 mg·kg-1, respectively, and their limits of quantitation( LOQ, S/N = 10) were 0. 040 mg · Kg-1 and 0.070 mg · Kg-1, respectively. After 48 hours of fumigation with cyanogen at 100 mg· Kg-1, the residues of cyanogen and its degradation product------hydrogen cyanide in aged soil were0. 32 mg ·kg-1 and 5. 68 mg · Kg-1, respectively. This method was also proved to be convenient in operation with high precision and accuracy, and could be applicable in the determination of cyanogen and hydrogen cyanide residues in aged soil.%采用吹扫捕集气相色谱法建立了土壤中熏蒸剂氰和氰化氢的分析方法,对土壤中氰和氰化氢预处理的吹扫温度、吹扫时间和吹扫载气(N2)流速进行了优化.最佳吹扫参数为:以10％ H2SO4溶液作溶剂、吹扫温度80℃、吹扫时间60 min和吹扫载气(N2)流速40mL·min -1.氰和氰化氢在0.2～10 mg·L-1质量浓度范围内线性关系良好,相关系数(r2)分别为o.9991和0.9983.在优化条件下,土壤中氰和氰化氢的平均回收率分别为95％和96％,相对标准偏差分别为3.6％和5.29％,检出限(S/N=3)分别为0.012、0.021 mg· kg-1,定量下限(S/N=10)分别为0.040、0.070mg· kg-1.用100 mg·kg-1氰熏蒸土壤48 h,氰及其降解产物氰化 氢在土壤中的残留量分别为0.32 mg·kg-1和5.68 mg·kg-1.该方法简便快速,精密度与准确度均符合要求,适用于土壤中氰和氰化氢残留量的检测.
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