Determination of Lead(II) with the Rotating Sample System

Abstract

As a result of industrialization lead is one of the most widely dispersed toxic heavy metals in the environment. There is a pressing need for a reliable, affordable and portable analytical technique for routine determination of lead at trace levels in biological and environmental samples. Despite their potential for portability and low cost, the currently available electrochemical stripping methods still have limited commercial availability. Among the reasons are the relatively large sample volumes and the large amount of reagents needed (1 ± 3 mL), lower than required precision, and the inconvenience of a rotated electrode system. The Rotating Sample System is a unique approach to electrochemical stripping, devised for 20 mL sample droplets utilizing a large surface area electrode. This design combines the advantages of a microelectrode and a rotated electrode system. The semispherical sample drop itself is rotated by a fine gas jet directed at it tangentially, eliminating the need for a sample container. Neither fine moving mechanical parts nor sophisticated controls are required. The detection limit for lead(II) was found low enough and the reproducibility is sufficient for routine determinations in biomedical samples (5 ppb, 6%). The system can support a CDC recommended screening for blood lead levels and an on-site analysis of environmental samples as well. Under suitable conditions calibration free direct determinations can also be performed.

Detection of Cd, Pb, and Cu in non-pretreated natural waters and urine with thiol functionalized mesoporous silica and Nafion composite electrodes

“…Until the SH-SAMMS ™ -Nafion sensors, this low concentration range of metal ions in un-pretreated natural waters has been extremely difficult to detect using mercury-free electrodes. Although others have reported the detection limits of Cd, Pb, and Cu to be in low ppb levels at either mercury based electrodes or mercury-free electrodes, the values were based on 3S/N and were measured in metal spiked buffered solutions rather than in real samples [40][41][42][43]. Simultaneous detection of Cd, Pb, and Cu in 0.01 M CH 3 COONa after 3 minutes of preconcentration in a very low concentration range (0 to 10 ppb), relevant to trace level assay of the metal ions was also demonstrated in Figure 6.…”

Electrochemical Oxidation Effect of Each Ascorbic Acid and Folic Acid on Lead Ions in Human Blood

“…The system can support a CDC recommended screening for blood lead levels and an on-site analysis of environmental samples as well. Under suitable conditions calibration free direct determinations can also be performed [20].…”

Desenvolvimento de sensor eletroquímico para monitoramento de chumbo em resíduos de disparos de armas de fogo

“…Eletrodos de mercúrio são a opção mais comum nas análises por stripping (Abdelsalam, M. E., et al, 2002, Baldo, M. A., et al, 2004, Cserey, A., 2004, Pizeta, I., et al, 2005) em função de algumas propriedades eletroquímicas, tais como a elevada sobretensão para a redução de prótons e a formação de amalgamas com diversos metais. Os eletrodos de mercúrio têm ainda a vantagem da possibilidade de uma renovação contínua da superfície eletródica com elevada repetibilidade.…”