Chandrawanshi Swati, Verma Santosh K, Deb Manas K
Pt. Ravishankar Shukla University, School of Studies in Chemistry, Raipur, Chhattisgarh 492010, India.
Government of Chhattisgarh, Home (Police) Department, State Forensic Science Laboratory, Raipur, Chhattisgarh 492001, India.
J AOAC Int. 2018 Jul 1;101(4):1145-1155. doi: 10.5740/jaoacint.17-0188. Epub 2017 Sep 28.
Perchlorate (ClO4-) is an environmental pollutant that affects human health. Perchlorate acts as a competitive inhibitor of iodine uptake in the thyroid gland (sodium-iodide symporter inhibitor); thus, its determination is important for public health concerns. Water and milk constitute a significant portion of the human diet. Because regular intake leads to an increase in perchlorate concentration in the human body, the estimation of perchlorate is of great concern. In this work, ion-pair single-drop microextraction (SDME) combined with attenuated total reflectance (ATR)-FTIR spectroscopy has been developed for the determination of perchlorate in bioenvironmental (soil, water, dairy milk, breast milk, and urine) samples. Perchlorate was extracted in a single drop of methyl isobutyl ketone as an - with the cationic surfactant cetyltrimethylammonuim bromide under optimized conditions. The strongest IR peak (at 1076 cm-1) was selected for the quantification of perchlorate among three observed vibrational peaks. Eight calibration curves for different concentration ranges of perchlorate were prepared, and excellent linearity was observed for absorbance and peak area in the range of 0.03-100 ng/mL perchlorate, with r values of 0.977 and 0.976, respectively. The RSDs (n = 8) for the perchlorate concentration ranges of 0.03-100, 0.03-0.5, 0.5-10, and 10-100 ng/mL were in the range of 1.9-2.7% for the above calibration curves. The LOD and LOQ in the present work were 0.003 and 0.02 ng/mL, respectively. The extracted microdrop was analyzed directly by ATR-FTIR spectroscopy. The parameters affecting SDME, i.e, effect of pH, stirring rate, reagent concentration, microdrop volume, and extraction time, were optimized, and the role of foreign species was also investigated. F- and t-tests were performed to check the analytical QA of the method. A noteworthy feature of the reported method is the noninterference of any of the associated ions. The results were compared with those of the ion chromatography MS method, and a high degree of acceptability was found. The method was successfully applied for the determination of perchlorate in bioenvironmental samples.
高氯酸盐（ClO4-）是一种影响人体健康的环境污染物。高氯酸盐是甲状腺中碘摄取的竞争性抑制剂（钠-碘同向转运体抑制剂）；因此，其测定对于公共卫生问题很重要。水和牛奶占人类饮食的很大一部分。由于经常摄入会导致人体中高氯酸盐浓度增加，因此高氯酸盐的评估备受关注。在这项工作中，已开发出离子对单滴微萃取（SDME）结合衰减全反射（ATR）-傅里叶变换红外光谱法用于测定生物环境（土壤、水、牛奶、母乳和尿液）样品中的高氯酸盐。在优化条件下，高氯酸盐在一滴甲基异丁基酮中与阳离子表面活性剂十六烷基三甲基溴化铵一起被萃取。在观察到的三个振动峰中，选择最强的红外峰（1076 cm-1处）用于高氯酸盐的定量。制备了不同高氯酸盐浓度范围的八条校准曲线，在0.03 - 100 ng/mL高氯酸盐范围内，吸光度和峰面积具有出色的线性，r值分别为0.977和0.976。对于上述校准曲线，0.03 - 100、0.03 - 0.5、0.5 - 10和10 - 100 ng/mL高氯酸盐浓度范围的相对标准偏差（n = 8）在1.9 - 2.7%范围内。本工作中的检测限和定量限分别为0.003和0.02 ng/mL。萃取的微滴通过ATR - 傅里叶变换红外光谱法直接分析。优化了影响SDME的参数，即pH值、搅拌速率、试剂浓度、微滴体积和萃取时间的影响，还研究了外来物种的作用。进行了F检验和t检验以检查该方法的分析质量保证。所报道方法的一个显著特点是任何相关离子均无干扰。将结果与离子色谱 - 质谱法的结果进行比较，发现具有高度可接受性。该方法已成功应用于生物环境样品中高氯酸盐的测定。
