尿样1.00 mL，加入1.0 g·L^-1乙酸-α-萘酯溶液10 μL，涡旋混合10 min后，加入0.1 mol·L^-1硫酸铜溶液0.1 mL，0.3 mol·L^-1萘胺溶液0.5 mL，50.0 g·L^-1亚硝酸溶液1 mL和1 mol·L^-1盐酸溶液0.1 mL，涡旋混合3 min。所得溶液在4℃冷藏10 min，再于50℃加热10 min。离心后，取有机相采用DB-5MS毛细管色谱柱进行气相色谱分离。质谱分析中采用选择反应监测模式。氰离子的质量浓度在0.1~10 mg·L^-1范围内与其色谱峰面积呈线性关系，检出限（3S/N）为0.015 mg·L^-1。按标准加入法进行回收试验，回收率在90.2%~106%之间，测定值的相对标准偏差（n=6）均小于3.5%。

The urine sample (1.00 mL) was mixed with 10 μL of 1.0 g·L^-1 α-naphthyl acetate solution for 10 min by vortex. 0.1 mol·L^-1 Copper sulfate solution, 0.5 mL of 0.3 mol·L^-1 naphthylamine solution, 1 mL of 50.0 g·L^-1 HNO₂ solution and 0.1 mL of 1 mol·L^-1 HCl solution were added into the solution, and the mixture was swirled for 3 min. The solution was refrigerated at 4℃ for 10 min, and then heated at 50℃ for 10 min. After centrifugation, the organic phase was separated by GC using DB-5MS capillary column. SRM was adopted in MS. Linear relationship between values of peak area and mass concentration of cyanide ion was found in the range of 0.1-10 mg·L^-1, with detection limit (3S/N) of 0.015 mg·L^-1. Test for recovery was made by standard addition method, giving results in the range of 90.2%-106%, with RSDs (n=6) all less than 3.5%.