Atomic absorption spectrometry, lead analysis

MDHS 14 General method for the gravimetric determination of respirable and total dust MDHS 15 Carbon disulphide MDHS 16 Mercury vapour in air Laboratory method using hopcalite adsorbent tubes, and acid dissolution with cold vapour atomic absorption spectrometric analysis MDHS 17 Benzene in air Laboratory method using charcoal adsorbent tubes, solvent desorption and gas chromatography MDHS 18 Tetra alkyl lead compounds in air Continuous on-site monitoring method using PAC Check atomic absorption spectrometry... 

Fang et al. [661] have described a flow injection system with online ion exchange preconcentration on dual columns for the determination of trace amounts of heavy metal at pg/1 and sub-pg/1 levels by flame atomic absorption spectrometry (Fig. 5.17). The degree of preconcentration ranges from a factor of 50 to 105 for different elements, at a sampling frequency of 60 samples per hour. The detection limits for copper, zinc, lead, and cadmium are 0.07, 0.03, 0.5, and 0.05 pg/1, respectively. Relative standard deviations are 1.2-3.2% at pg/1 levels. The behaviour of the various chelating exchangers used was studied with respect to their preconcentration characteristics, with special emphasis on interferences encountered in the analysis of seawater. 

Zhuang et al. [664] used palladium salts as a coprecipitation carrier for the concentration of cadmium, cobalt, and lead in seawater prior to analysis by atomic absorption spectrometry. 

Gardner and Yates [26] developed a method for the determination of total dissolved cadmium and lead in estuarine waters. Factors leading to the choice of a method employing extraction by chelating resin, and analysis by carbon furnace atomic absorption spectrometry, are described. To ensure complete extraction of trace metals, inert complexes with humic-like material are decomposed by ozone [27]. The effect of pH on extraction by and elution from chelating resin is discussed, and details of the method were presented. These workers found that at pH 7 only 1-2 minutes treatment with ozone was needed to completely destroy complexing agents such as EDTA and humic acid in the samples. 

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). 

Human activities often mobilize and redistribute natural compounds in the environment to an extent that they can cause adverse effects. Much attention has been paid to the determination of trace of pollutant elements on account of their significant effect on the environment. The potential of USAL has been put into use in environmental element analysis. Thus, the US leaching of cadmium from coals and pyrolysed oil shale prior to ETAAS [56] resulted in a twofold increase in precision, better detection limits and decreased background absorbance in relation to total digestion. Cadmium has also been successfully leached with US assistance from ash samples with subsequent flow-injection coid-vapour atomic absorption spectrometry [57]. Additional examples include the leaching of germanium from soiis with an uitrasonic probe in 10 min [58] or that of lead from coal in 60 s [59]. 

For chemical analysis of each sample, approximately 10 g of soil was transferred to a Gooch crucible. Surface debris such as twigs were removed, and the crucibles were heated in a muffle furnace at 500 °C for 24 h to remove organic components. The ashed soil was then pulverized with a pestle in a porcelain mortar. For each soil position, four 0.5-g portions of fine powder were analyzed separately, and the results were averaged. Soil analyses were performed in-house by atomic absorption spectrometry on a Varian Model 1250 spectrophotometer according to our previously reported method, which involves total dissolution of the sample in acid (11,12). The elements assayed were strontium, zinc, magnesium, calcium, sodium, lead, iron, aluminum, manganese, and potassium. 

Atomic Absorption Spectrometry. Flame atomic absorption spectrometry was adopted as the second method of analysis and since low volumes of air were sampled, only a limited number of elements were detected in the collected particles (calcium, copper, iron, magnesium, and zinc). Aluminum, cadmium, chromium, cobalt, lead, manganese, and nickel were not detected in any of the samples. This resulted in a limited... 

The uptake of aluminum, cadmium, chromium, cobalt, cop-per, iron, lead, magnesium, manganese, molybdenum, nickel, silver, tin, and zinc by B. subtilis Strain 168 is reported. These data were obtained during the lag phase, exponential phase, stationary phase, and the sporulation phase of the maturation cycle of this bacterial strain. Nonflame atomic absorption spectrometry was the method of analysis for all the metals except calcium, which was determined by flame atomic absorption spectrometry. The complete microbiological and analytical procedures are described. Uptake curves as a function of moles per cell, of moles per dry weight of a cell, and of percent available are reported. The data show that these metals seem to be required for growth. No attempts were made to postulate the roles played by these metals. 

Hsieh SAK, Chong YS, Tan JF and Ma TS (1982) Trace analysis of toxic metals. II Determination of lead, mercury, cadmium and thallium in foods by amperometry and atomic absorption spectrometry. Mikrochim Acta 2 337-346. 

Chemical analysis provides much more precise data about the sample, particularly the determination of metallic elements, mainly lead, cadmium, iron, calcium, sodium as well a.s anions, chlorides, fluorides, nitrates, carbonates and sulphates. The analyses are performed most frequently by spectrophotometry, atomic absorption spectrometry, or polarography in recent years radionuclide X-ray fluorescence and activation analysis have been used. 

N. Zhou, W. Freeh, and E. Lundberg, Rapid Determination of Lead, Bismuth, Antimony and Silver in Steels by Flame Atomic Absorption Spectrometry Combined with Flow Injection Analysis. Anal. Chim. Acta, 153 (1983) 23. 

Stoeppler, M., Brandt, K. and Rains, T.C. (1978). Contributions to automated trace analysis Part II. Rapid method for the automated determination of lead in whole blood by electrothermal atomic absorption spectrometry. Analyst, 103. 714-722. 

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