Electrothermal atomization accuracy

Accuracy When spectral and chemical interferences are minimized, accuracies of 0.5-5% are routinely possible. With nonlinear calibration curves, higher accuracy is obtained by using a pair of standards whose absorbances closely bracket the sample s absorbance and assuming that the change in absorbance is linear over the limited concentration range. Determinate errors for electrothermal atomization are frequently greater than that obtained with flame atomization due to more serious matrix interferences. 

The requirement for calibrated laboratory-ware for containing and dispensing solutions extends to all facets of the analytical procedure. It rests with the analyst to ascertain accuracy suitable to the application, of all devices used, including micropipets used in conjunction with electrothermal atomizers. The temptation to use other than appropriately calibrated containers, and chemical reagents of suitably high purity, and not to follow good analytical procedures as practised by those with only peripheral contact with analytical chemistry, should be avoided. 

Thirty-two sherds representing five different examples of Kayenta Anasazi Pueblo II pottery (Tusayan Corrugated [TC], Medicine Black-on-Red [MB], Tusayan Black-on-Red [TB], Dogoszhi Black-on-White [DB], and Sosi Black-on-White [SB]) have been analyzed for the elements As, Ba, Co, Cr, Cm, Fe, Mn, Ni, Pb, Se, V, and Zn by using the techniques of flame atomic absorption spectroscopy (.FAA) and electrothermal atomic absorption spectroscopy (ETAA). Analytical procedures for the chemical analysis of ceramics afford accuracy and sensitivity and require only a modest capital investment for instrumentation. The sherd samples were collected at two sites, one in southern Utah (Navajo Mountain [NM]) and the second in northern Arizona (Klethla Valley [KV]). These sites are approximately 60 km apart. Statistical treatment of the data shows that only three clay types were used in the 32 sherds analyzed, and that only three elements (Fe, Pb, and Ni) are necessary to account for 100% of the dispersion observed within this sample set. 

A procedure for the determination of molybdenum in serum, red blood cells, and urine is described. The low concentration of molybdenum in most unexposed individuals requires the sensitivity obtained using atomic absorption spectrophotometry and electrothermal atomization. Spike recovery tests indicate that low temperature ashing is required for accuracy. Severe matrix interferences preclude wet ashing or high-temperature ashing as sample pretreatments. Using the method described, it is possible to distinguish between industrially exposed and unexposed individuals. 

In this work the Eurachem guide [1] was used for the estimation of uncertainties involved in the determination by electrothermic atomic absorption spectrometry (EAAS) of manganese in digested lettuce leaves. The total uncertainty estimation was calculated assuming a 100% digestion efficiency with negligible uncertainty. The experimental precision was compared with an estimated one for the purpose of validation of the proposed method of evaluation. After this validation the uncertainty estimation was used in an accuracy test and in routine analysis with the support of a spreadsheet programme. 

The precision is typically 0.3-1% at absorbances larger than 0.1 or 0.2 for flame atomization and 1-5% for electrothermal atomization. The accuracy is generally limited by random error and noise to 0.5-5%, but may be affected by systematic errors due to spectral and chemical interferences. 

X-ray fluorescence (XRF) spectroscopy is useful for qualitative elemental analysis of paint samples. It does not require dissolution of the sample and can be applied to dry films. When an energy-dispersive instrument is employed, XRF provides rapid information on the presence of elements of atomic number higher than or equal to 12 (e.g., above magnesium). However, from a quantitative point of view, the sensitivity, accuracy, and reproducibility of XRF measurements is lower than that of flame, electrothermal, or plasma atomic spectrometry. 

Yang, K. X., Lonardo, R. E, Liang, Z., andYuzefovsky, A. I. (1997). Determination of tin in nickel-based alloys by electrothermal laser-excited atomic fluorescence with confirmation of accuracy by inductively coupled plasma mass spectrometry and atomic absorption spectrometry./ naf.ylr. Spearom. 12(3), 369. 

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