唾液中氰离子的五氟苄基溴衍生气相色谱法测定

Determination of cyanide ions in saliva using gas chromatography after derivatization with pentafluorobenzyl bromide

目的建立用五氟苄基溴(PFB-Br)衍生气相色谱法,电子捕获检测器(ECD)定量测定唾液中氰离子(CN-)的方法。方法取微量唾液,加入缓冲溶液后用乙腈稀释定容,加入定量的PFB-Br摇匀,沸水浴30.0 min进行衍生反应,冷却后直接进样入气相色谱仪分离,以ECD检测器检测。结果唾液中CN-的质量浓度在0.25~200.0 mg/L呈线性关系,线性相关系数为0.999 4;以100.0μl唾液量计算,方法最低检出浓度为0.07 mg/L,最低定量浓度为0.25 mg/L;方法的批间精密度为2.4%~5.3%(n=6),批内精密度为1.1%~3.8%(n=6),加标回收率为100.7%~102.1%。唾液常见的无机离子Cl^-、F^-和SCN^-对测定结果均无干扰。样品可在4℃保存至少15 d。结论该方法适用于唾液中氰离子测定,对氰化物中毒的应急检测有应用价值。

Objective To establish an analytical method for quantitative determination of cyanide ion in saliva based on gas chromatography with electron capture detector（ ECD） after derivatization with pentafluorobenzyl bromide（ PFB-Br）. Methods A small amount of saliva was diluted to volume with acetonitrile solution after being added buffer solution,then was added quantitative PFB-Br and shaken well. The samples which had been boiled 30 minutes for the derivative reaction were injected into the gas chromatograph directly to be separated after cooling,and then detected by ECD. Results The method showed that a good linearity range of cyanide ion mass concentration in saliva was 0. 25-200. 0 mg/L,and the linear correlation coefficient was0.999,4. The detection limit was 0. 07 mg/L and the minimum detection concentration was 0. 25 mg/L when saliva volume was100.0 μl. The between-run relative standard deviation（ RSD） was in the range of 2.4%-5.3%（ n = 6）,the within-run RSD was in the range of 1.1%-3.8%（ n = 6）,and the recovery rate was between 100.7% and 102.1%. The common inorganic ions as Cl^-,F^-and SCN^-in saliva had no interference to the determination results. The samples could be stored for at least 15 days in a refrigerator at 4 ℃. Conclusions This method is applicable for determination of cyanide ions in saliva and valuable for emergency detection of cyanide poisoning.