Spectrophotometric determination of trace amounts of Sb(III) and Sb(V) in water and biological samples by in-tube dispersive liquid-liquid microextraction and air-assisted liquid-liquid microextraction

This work compares two extraction methods for simultaneous preconcentration and spectrophotometric determination of Sb(III) and Sb(V) species in water and plasma samples. Sample preparation was achieved using air-assisted liquid-liquid microextraction (AA-LLME) and narrow-bore tube dispersive liquid-liquid microextraction (NT-DLLME) methods. Detection is based on the selective reaction between Sb(III) and bromopyrogallol red (BPR) at pH 6.4. Total Sb concentration was determined after reducing Sb(V) to Sb(III) in the presence of potassium iodide and ascorbic acid. Influential parameters on the extraction efficiency of the two methods were studied and optimized. Results show that NT-DLLME has more sensitivity than AA-LLME. Under the optimized conditions, limit of detection, limit of quantitation, and linear range for Sb(III) were 0.01, 0.03, and 0.03-20 ng mL(-1), respectively. Also, limit of detection, limit of quantitation, and linear range for Sb(V) were 0.03, 0.10, and 0.10-20 ng mL(-1), respectively. The precision, expressed as relative standard deviation, and enrichment factor were 3.5-4.7% and 95, respectively. Finally, the proposed method was applied to the determination of Sb(III) in the presence of Sb(V) and total Sb in water and plasma samples. [GRAPHICS] .

Automated summary

This study compared two extraction methods for simultaneous preconcentration and spectrophotometric determination of Sb(III) and Sb(V) species in water and plasma samples. The results showed that the NT-DLLME method had higher sensitivity and lower detection and quantitation limits under optimized conditions.