Anodic stripping voltammetry, lead analysis

Morrell G, Giridhar G. 1976. Rapid micromethod for blood lead analysis by anodic stripping voltammetry. Clin Chem 22 221-223. 

Scarponi et al. [781] studied the influence of an unwashed membrane filter (Millpore type HA, 47 mm diameter) on the cadmium, lead, and copper concentrations of filtered seawater. Direct simultaneous determination of the metals was achieved at natural pH by linear-sweep anodic stripping voltammetry at a mercury film electrode. These workers recommended that at least 1 litre of seawater be passed through uncleaned filters before aliquots for analysis are taken the same filter can be reused several times, and only the first 50-100 ml of filtrate need be discarded. Samples could be stored in polyethylene containers at 4 °C for three months without contamination, but losses of lead and copper occurred after five months of storage. 

Nygaard et al. [752] compared two methods for the determination of cadmium, lead, and copper in seawater. One method employs anodic stripping voltammetry at controlled pH (8.1,5.3 and 2.0) the other involves sample pretreatment with Chelex 100 resin before ASV analysis. Differences in the results are discussed in terms of the definition of available metal and differences in the analytical methods. 

Shams E, Abdollahi H, Yekehtaz M, Hajian R (2004) H-point standard additions method in the analysis by differential pulse anodic stripping voltammetry Simultaneous determination of lead and thin.Talanta 63 359-364. 

The determination of lead in soil is also discussed under Multi-Cation Analysis in Sects. 2.55 (inductively coupled plasma atomic emission spectrometry), 2.55 (atomic absorption spectrometry), 2.55 (photon activation analysis), 2.55 (emission spectrometry), 2.55 (anodic stripping voltammetry) and 2.55 (neutron activation analysis). 

De-proteinisation of diluted whole blood, and acid extraction of lead from proteins with 2M HNOs is the preparation chosen for the National Bureau of Standards reference method for blood-lead analysis [28]. Centrifugation of blood samples treated in this way yields clear supernatant fractions that contain all of the lead present, and which are easily dispensed into electrothermal atomisers using auto-sampling techniques. This method gave results that compared very well with those obtained using anodic stripping voltammetry, r = 0.975, for concentrations of 10—900 pg l-1 of lead in blood [15]. 

Flow-injection analysis is also well-suited for the automation of anodic stripping voltammetry. Metals can be plated from the sample solution as it passes over the electrode. Stripping is then carried out in the deox-ygenated carrier stream (15, 34). The sample itself does not have to be deox-ygenated. Detection limits of 3 nM have been reported for lead by this technique (34). 

For chemical monitoring, a list of priority substances has been established that includes metals such as cadmium, lead, and nickel. As far as metals are concerned, voltammetric techniques and more precisely electrochemical stripping analysis has long been recognized as a powerful technique in environmental samples. In particular, anodic stripping voltammetry (ASV) coupled with screen-printed electrodes (SPEs) is a great simplification in the design and operation of on site heavy metal determination in water, for reasons of cost, simplicity, speed, sensitivity, portability and simultaneous multi-analyte capabilities. The wide applications in the field for heavy metal detection were extensively reviewed (Honeychurch and Hart, 2003 Palchetti et al., 2005). 

A. Izquierdo, M.D. Luque de Castro, M. Valcarcel, Simultaneous determination of copper, lead, cadmium and zinc in previously lyophilized biological tissues using flow-injection analysis anodic-stripping voltammetry, Electroanal. 6 (1994) 894. 

Potentiometric stripping analysis, as stated in one review,92 "is not as general an analytical technique for the determination of metal traces as is graphite-furnace atomic absorption spectroscopy." It is used as a complementary technique for assay of some toxic metals in water (zinc, cadmium, lead, and copper in potable water and wastewater,93 94 and lead and thallium in seawater.95 The advantage of anodic stripping voltammetry (ASV) is summarized in two steps, which include electrolytic preconcentration and the stripping process. There are a number of interfering ions that can affect the... 

To minimize laboratory error and erroneous results due to contamination, blood specimens must be carefully collected after thorough cleaning of the skin with appropriate methods using lead-free blood containers and analyzed by a reliable laboratory. Under the standard, samples must be analyzed in laboratories which are approved by OSHA. Analysis is to be made using atomic absorption spectrophotometry, anodic stripping voltammetry or any method which meets the accuracy requirements set forth by the standard. 

There are many analytical techniques which may be used for lead analysis. These include X-ray fluorescence (XRF) spectroscopy, radioactivation methods, emission spectrography, ring oven methods, polarographic techniques [including anodic stripping voltammetry (ASV)], spark source mass spectrometry, colorimetry and atomic absorption spectrometry (AAS). Background information upon all of these methods may be found in the Handbook of Air Pollution Analysis [1]. 

Laboratory analysis of lead in paint chips should only be carried out by those laboratories certified for such analyses by the U.S. EPA National Lead Laboratory Accreditation Program (NLLAP), using approved laboratory methods. Use of AAS methodology, particularly in the ICP-AAS configuration, is the common approach. Another routine method is anodic stripping voltammetry (ASV). 

Anodic stripping voltammetry is an electroanalytical analysis method, that can be employed in the study of many metals [74]. Lead is analyzed by selective deposition on an electrode (reduction) to facilitate concentration. The lead is then stripped (oxidized) by a linearly variable applied voltage, with the output being a plot of current and voltage in which peak area corresponds to the oxidation of lead. The method is accurate and reliable to the 1 pg/L level [73]. 

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