苦味酸可与次氯酸钠反应生成的氯化苦(三氯硝基甲烷),用SPT37.50吹扫捕集仪吹扫、捕集及热解析后,经DB-624毛细管色谱柱分离,用电子轰击电离源及选择离子监测模式进行质谱分析。据此建立了吹扫捕集-气相色谱-质谱法间接测定饮用水源水中苦味酸含量的方法。苦味酸的质量浓度在25 μg·L-1以内与其峰面积呈线性关系,方法检出限(3S/N)为0.9 μg·L-1。样品加标回收率在86%~132%之间。

Chloropicrin (nitrotrichloromethane) was generated by reacting picric acid with NaClO, purged and trapped, and thermodesorbed using the SPT37.50 purge and trap concentrator. DB-624 capillary column was used for separation, and EI ion source with selected ion scanning mode were adopted in MS analysis. Based on these factors, a method of GC-MS with purge and trap concentrator for the indirect determination of picric acid in drinking source water was proposed. Linear relationship between values of peak area and mass concentration of picric acid was obtained in the range within 25 μg·L-1, with detection limit (3S/N) of 0.9 μg·L-1. Test for recovery was made by standard addition method, giving values of recovery in the range of 86%-132%.