Sono-Electroanalytical Determination of Lead in Saliva

Ultrasonically Enhanced Voltammetric Analysis and Applications: An Overview

“…However, it was observed that after 9 additions of salvia the electrode becomes rapidly passivated even with insonation. The optimum sputum size of 220 mL À1 was consequently a comprise between the maximum concentration of lead introduced to the cell and minimizing the electrode passivation in order to maintain quantitative ultrasonic depassivation [129]. The observed linear calibration intersected the origin, with the results showing good intrasample reproducibility [129] with the theoretical limit of detection was found to be 0.25 mg L À1 for a 220 mL sputum corresponding to a salivary lead concentration of 38 mg L À1 .…”

“…The optimum sputum size of 220 mL À1 was consequently a comprise between the maximum concentration of lead introduced to the cell and minimizing the electrode passivation in order to maintain quantitative ultrasonic depassivation [129]. The observed linear calibration intersected the origin, with the results showing good intrasample reproducibility [129] with the theoretical limit of detection was found to be 0.25 mg L À1 for a 220 mL sputum corresponding to a salivary lead concentration of 38 mg L À1 . This compares with previous analyzes for lead in biological media such as blood using a vibrating glassy carbon electrode [137] where accurate results, with a sample digestion pretreatment, were limited to the concentration range of 22 ± 616 mg L À1 .…”

“…Saliva [129] There is a need for the development for portable, quick and accurate analysis for monitoring lead in employees in lead based industries. The usual procedure is a blood test, but it has been found that workers can have extremely high levels of lead in sweat and saliva, even though their lead level in blood is only moderately elevated [130].…”

“…A plot of peak area vs. total lead concentration did not intersect the orgin, showing that the stripping of lead proceeds with very little overpotential in either direction. Second, ultrasound is introduced in the preconcentration step at 30 W cm À2 from a 30 kHz horn [129]. The forced convection is evident by the increase in peak size shown in Figure 8.…”

“…The concentration range of lead in saliva is of the order of 0 ± 300 mg L À1 , for a sputum size of 0.2 ± 0.5 mL of saliva to total cell volume 35 mL the concentration range in the analyte is therefore of the order 0 ± 10 mg L À1 . The sensitivity of LS-ASV to standard additions over the range 1.25 ± 11.25 mg L À1 was investigated on a glassy carbon electrode with a preconcentration at 30 W cm À2 which was found to be unsatisfactory owing to ablation affects [129]. Due to simultaneous oxidation and reduction occurring on the electrode substrate a Nafion coated mercury thin film glassy carbon (NCMTFGCE) electrode was consequently employed.…”