Optimization of CE separation of roxarsone and several arsenic compounds

Abstract

Elektroforesis rerambut dengan pengesanan ultralembayung digunakan bagi pemisahan arsenit As(III), arsenat As(V), asid monometilarsonik (MMA), asid dimetilarsinik (DMA), asid fenilarsonik (PAA), asid ρ–arsanilik (ρ–ASA) dan roksarson (3–NHPAA). Pemisahan tercapai menggunakan kapilari silika terlakur dengan sel pengesan berkepekaan tinggi dan pengesan susun atur diod. Larutan penimbal 15 mM fosfat digunakan sebagai elektrolit latarbelakang. Pengaruh pH elektrolit, keupayaan yang dikenakan dan panjang gelombang pengesanan dikaji dengan nilai optimum diperoleh pada pH 6.0, keupayaan 25 kV dan panjang gelombang pengesanan pada 191 nm. Kaedah yang telah dioptimum ini memberi had pengesanan 0.193 mg/L bagi As(III). Kebolehulangan bagi semua analit adalah di antara julat 4.6%–10.5% RSD. Capillary electrophoresis with direct UV detection was used for the separation of arsenite As(III), arsenate As(V), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), phenylarsonic acid (PAA), ρ–arsanilic acid (ρ–ASA) and roxarsone (3–NHPAA). The separation was achieved in a fused silica capillary using a high sensitivity detection cell with diode array detector. A 15 mM phosphate buffer was used as the background electrolyte. The influence of electrolyte pH, applied voltage and wavelength were investigated in this research where the optimum conditions obtained were at pH 6.0, 25 kV voltage and 191 nm detection wavelength. The optimized method provided a limit of detection of 0.193 mg/L for As(III). Reproducibility of the analytes was in the range of 4.6%–10.5% RSD.