Solidified Floating Organic Drop Microextraction–electrothermal Atomic Absorption Spectrometry for the Determination of Trace Amounts of Lead in Water Samples

Abstract

Solidified floating organic drop microextraction (SFODME) was utilized as a separation or pre-concentration step prior to electrothermal atomic absorption spectrometric (ETAAS) determination of ultra-trace amounts of lead. The method was based on the formation of an extractable complex between Pb(II) and 1-(2-pyridylazo)-2-naphathol (PAN) as a chelating agent. The main parameters affecting the performance of SFODME, namely, type and volume of organic solvent, pH, concentration of the chelating agent, extraction time, stirring rate, extraction temperature, disperser solvent, ionic strength, and interference effect were investigated and optimized. Under optimized experimental conditions a pre-concentration factor of 22.03 and a detection limit of 0.064 μg L -1 for the pre-concentration from 13.0 mL water sample was achieved. The relative standard deviation of the measurements in the range of 1.3 -2.5% (n = 6). The proposed method was assessed through the analysis of certified reference water and recovery experiment with satisfactory results.Keywords: solidified floating organic drop microextraction, lead, electrothermal atomic absorption spectrometry, water samples Abstract Pengekstrakan mikro pemejalan titisan organik terapung (SFODME) digunakan sebagai langkah pemisahan atau pemekatan sebelum penentuan jumlah surih plumbum ditentukan menngunakan spektrometri serapan atom elektrotermal (ETAAS). Kaedah ini berasaskan kepada pembentukkan kompleks yang boleh diekstrak di antara Pb(II) dan 1-(2p-piridilazo)-2-naphol (PAN) sebagai agen pengkelat. Parameter utama yang memberi kesan kepada prestasi SFODME iaitu jenis dan isipadu pelarut organik, pH, kepekatan agen pengkelat, masa pengekstrakan, kesan pengacauan, suhu pengesktrakan, pelarut serakan, kekuatan ionik dan kesan gangguan telah dikaji dan dioptimumkan. Keadaan optimum bagi eksperimen diperolehi dengan faktor pemekatan pada 22.03 dan had pengesanan dicapai pada 0.064 μg L -1 bagi pemekatan 13.0 mL sampel air. Pengukuran sisihan piawai relatif berada pada julat 1.3 -2.5% (n = 6). Kaedah yang dicadangkan juga dinilai melalui analisis sampel air rujukan yang disahkan dan ujian perolehan semula yang mencapai keputusan memuaskan.Kata kunci: pengekstrakan mikro pemejalan titisan organik terapung, plumbum, spektrometri serapan atom elektrotermal, sampel air