离子色谱-串联电喷雾质谱法检测自来水中二氯乙酸和三氯乙酸

建立了一种采用离子色谱-串联电喷雾四级杆质谱联用技术检测自来水中可致癌的饮用水消毒副产物二氯乙酸和三氯乙酸的方法。该方法使用IonPacPrototype-10高容量阴离子交换柱为分离柱,以ICS-3000多功能色谱系统的淋洗液自动发生装置在线产生不同浓度的KOH淋洗液,在合适的梯度条件下,实现对自来水样品中两种卤代乙酸和多种常见阴离子的高效分离,经抑制器将淋洗液抑制为近中性后,在不添加有机溶剂的情况下,进入API3200 ESI-MS/MS质谱系统,选取适合的离子对和温度、能量条件,进行准确定量分析。在优化的色谱和质谱条件下,二氯乙酸和三氯乙酸的检出限分别为0.053和0.46μg/L。峰面积校正曲线的线性范围均跨越两个数量级以上。对4种不同浓度的标准溶液和实际样品连续9次进样,峰面积的相对标准偏差小于7%。选取北京市18个区县及全国部分省市的自来水样品进行检测,所得结果令人满意。挑选其中的典型样品进行不同浓度的标准加入实验,回收率在86.7%-119.0%之间。

Determination of Trace Disinfection By-products Dichloroacetic Acid and Trichloroacetic Acid in Tap Water by Ion Chromatography-Electrospray-Tandem Mass Spectrometry

This study developed a new method on the determination of carcinogenic disinfection by-products(DBPs)-trace dichloroacetic acid and trichloroacetic acid in tap water by ion chromatography-electrospray-tandem mass spectrometry(IC-ESI-MS/MS).The separation of two haloacetic acids(HAA2) and the KOH gradient eluents were generated by Eluent Generator of ICS-3000.After the suppressor in which the eluents were suppressed to be neutral pH,API3200 ESI-MS/MS was employed to detect and measure analytes under appropriate MS conditions without adding any organic solvent.In the case of HAA2,optimised IC and MS parameters including eluent gradient,temperature and collision energy etc.brought high sensitivity in which the minimal detection limits(MDLs) of DCAA and TCAA were 0.053 g/L and 0.46 g/L while the correlation coefficients(R) of calibration curves who that might calibrate over two orders of magnitude were 0.9999 and 0.9992 respectively.Relative standard diviations of the peak area for nine successive injections of four-different-concentration standard solutions and two actual samples were all lower than 7%.Over than 60 tap waters samples that were collected from 18 boroughs or counties in Beijing and other cities or towns in China were chosen fro the measurement,the results were satisfied.The recoveries of spiked standard were between 86.7% and 119.0% for five typical samples multiply at four different standard concentrations.