Kolling Leandro, Zmozinski Ariane Vanessa, Rodrigues Vale Maria Goreti, Messias da Silva Márcia
Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, CEP 91501-970, Brazil.
Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, CEP 91501-970, Brazil; Instituto Nacional de Ciência e Tecnologia do CNPq - INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, Bahia, CEP 40170-115, Brazil.
Talanta. 2019 Dec 1;205:120105. doi: 10.1016/j.talanta.2019.06.105. Epub 2019 Jul 3.
In this work a simple and practical method for the determination of Pb and Ni in automotive gasoline by solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry was investigated. In the proposed method, disks of filter paper were used to pre-concentrate and store Pb, Ni and other trace elements from automotive gasoline samples. For this, a volume of sample was deposited and dried out on a filter paper disk previously adapted into a polytetrafluoroethylene mold, and then the gasoline-embedded filter paper was either cut into small pieces or pulverised and introduced directly into the graphite furnace for trace element determination. Temperature program, use of chemical modifier, chromatographic effect and volume of sample were investigated. Calibration curves using organic and inorganic standards of the analytes as well as external and internal calibration methods were evaluated. Using optimised conditions, characteristic masses and limits of detection of 6 and 11 pg, and 0.5 and 2.1 μg L were found for Pb and Ni, respectively. The accuracy of the method was evaluated with spike-recovery tests and a certified reference material of wear lubricant oil. The spike-recovery tests were accomplished for 9 samples and the best results were obtained with the pulverised filter paper. A second method that employs a transversely heated filter atomiser was applied as a comparative one. The filter paper was shown to be a simple and inexpensive tool for storage and transportation of gasoline samples, and it allowed the pre-concentration of the analytes, since a larger volume of sample can be dried out on it.
本工作研究了一种采用固体进样高分辨率连续光源石墨炉原子吸收光谱法测定车用汽油中铅和镍的简单实用方法。在所提出的方法中，使用滤纸圆盘对车用汽油样品中的铅、镍及其他微量元素进行预富集和储存。为此，将一定体积的样品沉积并干燥在预先适配于聚四氟乙烯模具中的滤纸圆盘上，然后将嵌入汽油的滤纸切成小块或粉碎，直接引入石墨炉进行微量元素测定。研究了温度程序、化学改进剂的使用、色谱效应和样品体积。评估了使用分析物的有机和无机标准以及外标和内标法的校准曲线。在优化条件下，铅和镍的特征质量分别为6和11 pg，检测限分别为0.5和2.1 μg/L。通过加标回收试验和磨损润滑油的有证标准物质评估了该方法的准确性。对9个样品进行了加标回收试验，使用粉碎后的滤纸获得了最佳结果。应用了另一种采用横向加热滤光片雾化器的方法作为对比方法。结果表明，滤纸是一种用于储存和运输汽油样品的简单且廉价的工具，并且由于可以在其上干燥更大体积的样品，因此它能够对分析物进行预富集。
