Analytical Chemistry Research and Development Group (QUIANID), LISAMEN - CCT - CONICET - Mendoza, Av Ruiz Leal S/N Parque General San Martín, M 5502 IRA Mendoza, Argentina.
Talanta. 2010 Mar 15;80(5):2034-40. doi: 10.1016/j.talanta.2009.11.012. Epub 2009 Nov 12.
A highly efficient single-drop microextraction (SDME) procedure using a low-cost room temperature ionic liquid (RTIL), i.e., tetradecyl(trihexyl)phosphonium chloride (CYPHOS IL 101), for Pb determination at trace levels in real water samples was developed. Lead was chelated with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) reagent and extracted into a 4 microL microdrop of CYPHOS IL 101. The RTIL drop was directly injected into the graphite furnace of the electrothermal atomic absorption spectrometer (ETAAS). Under optimal microextraction conditions, a preconcentration factor of 32 was achieved with only 1.5 mL of sample resulting in a phase-volume ratio of 375. The limit of detection (LOD) obtained was 3.2 ng L(-1) and the relative standard deviation (RSD) for 10 replicates at 0.5 microg L(-1) Pb(2+) concentration level was 4.9%, calculated at peak heights. The calibration graph was linear from concentration levels near the detection limits up to at least 4.5 microg L(-1) with a correlation coefficient of 0.9996. The accuracy of the methodology was evaluated by analysis of a certified reference material (CRM). The method was successfully applied to the determination of Pb in tap, mineral, well and river water samples.
开发了一种使用低成本室温离子液体（RTIL），即十四烷基（三己基）氯化膦（CYPHOS IL 101），进行痕量水中 Pb 测定的高效单液滴微萃取（SDME）程序。Pb 与 2-（5-溴-2-吡啶偶氮）-5-二乙氨基苯酚（5-Br-PADAP）试剂螯合，并萃取到 4μL 的 CYPHOS IL 101 微滴中。将 RTIL 微滴直接注入电热原子吸收光谱仪（ETAAS）的石墨炉中。在最佳微萃取条件下，仅需 1.5 mL 样品即可实现 32 倍的预浓缩因子，导致相体积比为 375。得到的检出限（LOD）为 3.2ng L(-1)，在 0.5μg L(-1) Pb(2+)浓度水平下，10 个重复的相对标准偏差（RSD）为 4.9%，以峰高计算。校准曲线从检测限附近的浓度水平到至少 4.5μg L(-1)呈线性，相关系数为 0.9996。通过分析认证参考物质（CRM）评估了该方法的准确性。该方法成功应用于自来水中 Pb 的测定、矿泉水、井水和河水样品。
