Switchable hydrophilic solvent liquid-liquid microextraction-anodic stripping voltammetry for determination of lead ions in glyceryl triacetate

A method based on switchable hydrophilic solvent liquid-liquid microextraction and anodic stripping voltammetry was developed for the rapid determination of lead ions in glyceryl triacetate samples. The liquid-liquid microextraction was first used to pretreat glyceryl triacetate samples. The buffer solution of the extractant, the amount of NaOH added, the amount of APDC used as a chelating agent and the solvent volume of the dispersant after extraction were studied, and a series of optimal pretreatment methods for glyceryl triacetate were developed. An electrochemical sensing method for the determination of lead ions was also developed by modifying a screen-printed electrode with bismuth nanoparticles. Finally, a method for the determination of lead ion residues in glyceryl triacetate samples was developed by combining the above two methods. The results showed that: 1) Under the optimized experimental conditions, the linear range for the determination of lead ions in glyceryl triacetate samples was 2-16 mg/kg, the linear regression equation was y=0.411 5x+3.957 2 with R² of 0.995 4, and the detection limit was 0.110 mg/kg. 2) The anode stripping voltammetry method could realize the determination of lead ions within 5 min. 3) The average recoveries and relative standard deviations were 96.5%-99.6% and 0.79%-3.87%, respectively. 4) The developed method was accurate and comparable to atomic absorption spectrometry and inductively coupled plasma mass spectrometry for the same determination. This method is simple, fast and accurate, and could rapidly and sensitively determine the trace lead ions in glyceryl triacetate samples.