Lead analysis

Workers who produce or use lead should be aware of possible ha2ards. Symptoms of chronic lead poisoning include fatigue, headache, constipation, uneasy stomach, irritabiHty, poor appetite, metallic taste, weight loss, and loss of sleep. Most of these same symptoms also occur in many common illnesses, such as the flu, thus a physician must rely on tests, such as blood lead analysis, to determine chronic lead poisoning. 

Braithwaite RA, Girling AJ (1988) Bovine reference materials for accuracy control of blood lead analysis. Fresenius Z Anal Chem 332 704-709. 

As microwave sample preparation has evolved, standard microwave procedures have been developed and approved by numerous standard methods organisations (ASTM, AOAC International, EPA, etc.), see ref. [64]. Examples are standard test methods for carbon black/ash content (ASTM Method D 1506-97), lead analysis in direct paint samples (ASTM Method E 1645-94), etc. Table 8.15 shows some microwave ashing references (detection weight). A French AFNOR method utilises the atmospheric pressure single-mode microwave method as an alternative sample preparation procedure for Kjeldahl nitrogen determination [84], The performance of a microwave-assisted decomposition for rapid determination of glass fibre content in plastics for QC has been described [85]. 

Outdoor lead dust was found to be a more potent contaminant of children s hands than indoor lead dust at day care centers in New Orleans boys, in general, had higher hand lead levels than girls. The conclusions were based on lead analysis of hand wipe samples taken before and after children played outdoors at four different day care centers (a private inner-city site, a private outer-city site, a public inner-city site, and a public outer-city site). The private inner-city site had a severely contaminated outdoor play area with measured soil lead concentrations ranging from 287 to 1,878 mg/kg. The outdoor play area at the public inner-city site, where children exhibited the lowest hand lead measurements of any site in the study, had been completely paved over with concrete or rubberized asphalt and had well-maintained equipment (Viverette et al. 1996). 

ASTM. 1998c. ASTM E 1645. Standard practice for the preparation of dried paint samples for subsequent lead analysis by atomic spectrometry. American Society for Testing and Materials. 

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

Patterson CC, Settle M (1976) The reduction of orders of magnitude errors in lead analysis. In LaFleur PD (ed) Accuracy in trace analysis sampling, sample handling, analysis. NBS Special Publication 422, p. 321... 

At 252 °C based on kg/ks = 0.15 reaction (9) accounts for only 34 % of the ethane and 11 % of the ethylene. Reactions (6) and (7) are required to explain the concordance of results based on gas analysis and with those based on tetramethyl lead analysis. All observed orders and activation energies are consistent with this mechanism. If reaction (1) is the rate-controlling step in the initiation, the rate of this reaction can be calculated from... 

The selectivity (or specificity ratio) is useful for defining the magnitude of an analytical interference for real situations. Photon ratios serve only to demonstrate the demands upon the spectrometer. The selectivity ratio is the concentration of interfer-ent that causes a unit concentration error in the analyte. If the selectivity ratio of 2000 (defined as adequate by industry)(41) is used, the apparent lead concentration in the bone ash will be 250 ppm. A calcium/lead selectivity ratio of 5,000,000 is required to achieve an analytical accuracy of 10 per cent for one ppm lead in bone ash. (The authors are aware of a lead analysis for bone ash containing approximately 30 ppm lead that was reported by an ICP laboratory to contain approximately 550 ppm lead.) In this instance the selectivity ratio was only 1 x 103. 

Lead Analysis by TEMS. Lead analyses are made using the gel technique described by Cameron et al. (10). Lead ions are thermally produced at rhenium filament temperatures between 1100-1300°C, depending on the sample size. Ten ng of sample allows an analysis of 10 runs with 200 sweeps each across the masses of interest. 

C.-C. Yang, A.S. Kumar and J.-M. Zen, Precise blood lead analysis using a combined internal standard and standard addition approach with disposable screen-printed electrodes, Anal. Biochem., 338 (2005) 278-283. 

If lead analysis is performed by AA spectrophotometry, following acid digestion of samples, then the stoichiometric calculation for tetraethyllead (TEL) may be done as follows ... 

Table 4 Performances of the participants in the proficiency testing for lead analysis in the spiked pure water...

Spiked pure water mean and uncertainty (2x SD) for Lead analysis... 

Fig. 7 Repartition of results for lead analysis in the matrix CRM by the 45 laboratories...

This bias in lead analysis was observed for all the methods used by laboratories atomic absorption (flame and furnace), ICP (optical and MS), and other methods, as shown in Fig. 9. This bias was not observed for cadmium, and means of the different methods were very close to the reference value. 

Analysis of a matrix CRM has shown a noteworthy bias in lead analysis of about 10%. This bias was observed for all routine methods used by laboratories. Complementary experiments have indicated that a strong matrix effect was responsible for this bias. This underlined bias has demonstrated that for this matrix water, only a primary method can provide the true value of the sample of an inter-laboratory comparison. The mean value of laboratory results cannot be used as a reference value. 

Johnson, D.K., S.M. Combs, J.D. Parsen, et al. 2002. Lead analysis by anti-chelate fluorescence polarization immunoassay. Environ. Sci. Technol. 36 1042-1047. 

Lead. Lead poisoning has always been a well recognized problem In Industrial hygiene as well as a public health problem. The Interest In lead analysis Is reflected In the NIOSH PAT program where lead Is one of the three metals routinely analyzed from filter samples and In the Center for Disease Control (CDC) quality assurance program for the analysis of lead In biological matrixes. 

The method described was included among those covered by the accreditation granted by BELAC, that is, the official organization in charge of quality management in Belgium. It can be concluded that reliable results in trace lead analysis may be affected by the purity and surface properties of labware, which can impact on the quality and accuracy of the method in ultra-trace analysis. 

Originally, this method of sample introduction was devised for specific applications (e.g., Cemik s punched-disc of filter paper for blood lead analysis [6], and the analysis of metalloproteins separated on cellulose acetate membranes [7]), but there is now a commercially available system that uses carbon boats which has been recently applied to the direct analysis of cadmium and lead in blood and urine [ 8]. 

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]. 

The most useful index of excessive exposure to lead is a blood-lead analysis, and the majority of methods discussed here are concerned with this measurement. Many of the earlier ETA—AAS methods used little or no sample pretreatment and in almost all cases the variety of matrix interferences encountered necessitated strict control of ETA conditions, and made calibration by standard additions mandatory. The problem of diffusion of liquid blood samples into the graphite atomisers was overcome as an... 

Adsorption capacities were studied -by Atomic Emission Spectroscopy (Vista-Pro ICP-OES from VARIAN) for lead analysis and -by UV Spectrometry (Nicolet Evolution 300 from ThermoElectron Corporation) for p-nitrophenol determination. 

Remarks on Table a)LA content was detd by measuring the nitrogen concent of the sample and calcg % LA [See US Ordnance Corps Gasometric Method, item III C a, under Lead Azide Plant, Analytical Procedures] b)The % lead in a sample on a LA basis is always less than that given by a total lead analysis (See item III D, under Lead Azide Plant, Analytical Frocediires), A sample calcn showing this is outlined below mw of Pb(Ns). 291-26 at wt of Pb 207.21 and % Pb in Pb(N,)j 207,21/291.26 71.08. if... 

Total lead analysis. It is recommended that 100 ml of the water sample is introduced into a pre-cleaned and rinsed polyethylene container with a polypropylene cap, or into a glass bottle. In both cases, acidify the water to pH < 2 with nitric acid. Ensure that the container is completely full of the sample. In this situation, the sample can be held for up to six months for the analysis of total lead. 

The food they bought is free of lead. The dishes they use at home are the source of the lead. Determine whether the dishes contain lead. Analysis of the pottery showed that lead was present in the glaze. 

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