液相色谱-串联质谱法与离子色谱-串联质谱法测定食品中氯酸盐和高氯酸盐方法比较研究

Comparison of liquid chromatography-tandem mass spectrometry and ion chromatography-tandem mass spectrometry for the determination of chlorate and perchlorate in foods

中文关键词:  氯酸盐  高氯酸盐  离子色谱-串联质谱  液相色谱-串联质谱

英文关键词:chlorate  perchlorate  liquid chromatography-tandem mass spectrometry  ion chromatography- tandem mass spectrometry

中文摘要:

      目的 考察离子色谱-串联质谱法(ion chromatography-tandem mass spectrometry, IC-MS/MS)和液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry, LC-MS/MS)在测定不同食品中氯酸盐和高氯酸盐的一致性。方法 利用乙腈/水(3:2, V:V)提取鸡蛋、奶粉和菠菜中的目标物, 经石墨化炭黑(graphitized carbon black, GCB)小柱净化, 以IonPacTM AS20离子色谱柱和CSHTM Fluoro-Phenyl液相色谱柱为分析柱, 三重四极杆质谱仪检测, 内标法定量。对两种方法测得的数据进行正态性检验和差异性分析。比较两种方法的保留时间漂移, 考察色谱稳定性。对两种方法测得的浓度进行线性回归和Bland-Altman (B-A)图可视化考察方法一致性。结果 两种方法测得氯酸盐(高氯酸盐)的质量浓度在1~500 (0.1~50.0) g/L范围内线性良好(r2>0.999)。IC-MS/MS与LC-MS/MS测定高氯酸盐的定量限均为0.5 g/kg, 氯酸盐的定量限分别为5.7 g/kg和4.2 g/kg。回收率范围分别为82.3%~107.4%和94.8%~109.4%, 相对标准偏差分别为1.5%~13.6%和1.2%~9.6%。IC-MS/MS(LC-MS/MS)测得鸡蛋、奶粉、菠菜中氯酸盐和高氯酸盐的基质效应分别为12.1% (22.1%)、9.0% (27.4%)、–24.0% (–11.8%)和–16.8% (–18.5%)、–18.6% (–28.4%)、–20.2% (–21.1%)。线性回归法显示两种方法测定氯酸盐和高氯酸盐浓度的回归曲线斜率分别为1.0144和1.0908。B-A图显示绝大多数数据点位于平均值±1.96标准偏差范围。结论 两种方法的准确度和精密度均符合化学检验方法验证通则的要求, 两种方法测得的氯酸盐、高氯酸盐浓度结果基本一致, 但氯酸盐在LC-MS/MS系统中的保留时间稳定性更好, IC-MS/MS在测定食品中氯酸盐、高氯酸盐时的抗基质干扰能力更强。

英文摘要:

      Objective To examine the consistencies between ion chromatography-tandem mass spectrometry (IC-MS/MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the determination of chlorate and perchlorate in different foods. Methods The targets in eggs, milk powder and spinach were extracted using acetonitrile/water (3:2, V:V), cleaned up by graphitized carbon black (GCB) cartridge, using IonPacTM AS20 ion chromatography column and CSHTM Fluoro-Phenyl liquid chromatography column for separation, respectively, detection with triple quadrupole mass spectrometer, quantification through internal standard method. The resulted data were tested for normality and differences. The retention time drifts of the two methods were compared to investigate the chromatographic stability. Linear regression and Bland-Altman (B-A) plot visualization of the concentrations measured by both methods were performed to examine method consistency. Results The mass concentration of chlorate (perchlorate) measured by 2 kinds of methods showed good linearity within the range of 1–500 (0.1–50.0) μg/L (r2>0.999). The limits of quantitation for the determination of perchlorate by IC-MS/MS and LC-MS/MS were both 0.5 μg/kg, while the limits of quantitation for chlorate were 5.7 μg/kg and 4.2 μg/kg, respectively. The recoveries of the targets measured by IC-MS/MS (LC-MS/MS) ranged from 82.3% to 107.4% (94.8%-109.4%) with the relative standard deviations of 1.5%–13.6% (1.2%–9.6%). The matrix effects of chlorate and perchlorate in eggs, milk powder, and spinach measured by IC-MS/MS (LC-MS/MS) were 12.1% (22.1%), 9.0% (27.4%), –24.0% (–11.8%), and –16.8% (–18.5%), –18.6% (–28.4%), and –20.2% (–21.1%), respectively. The linear regression method showed that the slope of the regression curves for the determination of chlorate and perchlorate concentration by the two methods were 1.0144 and 1.0908, respectively. The B-A chart showed that the vast majority of data points are within the mean±1.96 standard deviation range. Conclusion The accuracy and precision of the two methods are complied with the general principles for the validation of chemical test methods. The results of the chlorate and perchlorate concentrations measured by the two methods exhibited good consistency, but the retention time stability of chlorate in the LC-MS/MS system is better, and the capability of IC-MS/MS to reduce the matrices interference is superior to LC-MS/MS during the determination of chlorate and perchlorate in foods.