Air-assisted liquid–liquid microextraction combined with flame atomic absorption spectrometry for determination of trace Pb in biological and aqueous samples

ABSTRACT

A fast, inexpensive, environmental-friendly and efficient sample preparation method for determination of trace amounts of Pb²⁺ ions in aqueous samples and humane urine is presented. Lead was extracted using the air-assisted liquid–liquid microextraction (AALLME) technique and determined by flame atomic absorption spectrometry (FAAS). O, O-diethyl dithiophosphoric acid was used as a chelating agent to form a hydrophobic complex. Several factors influencing the microextraction efficiency and the complex formation such as extraction solvent type and its volume, pH, concentration of the chelating agent and extraction time were evaluated. Under optimum conditions, the calibration graph was linear in the concentration range of 30–350 μg L⁻¹ with a detection limit of 8.5 μg L⁻¹. The relative standard deviation for six replicated measurements of 140 μg L⁻¹ of Pb²⁺ was 4.07%. Obtained enrichment factor was 25. Through combination of AALLME with FAAS, the analytical performance of FAAS for the detection of lead greatly improved. The accuracy of the developed method was evaluated by the analysis of the certified reference material and addition recovery test. The presented method was able to analyse lead in different real samples including human urine, wastewater and water samples with satisfactory recovery ranged from 95% to 108%.

KEYWORDS:

• Air-assisted liquid–liquid microextraction
• flame atomic absorption spectrometry
• Pb²⁺
• environmental water
• OO- diethyl dithiophosphoric acid
• urine

Acknowledgments

The author thank the Research Council of Azarbaijan Shahid Madani University for the financial support.

Disclosure statement

No potential conflict of interest was reported by the author.