Sturgeon Analysis

In similar work, Sturgeon et al. [125] compared direct furnace methods with extraction methods for cadmium in coastal seawater samples. They could measure cadmium down to 0.1 pg/1. They used 10 pg/1 ascorbic acid as a matrix modifier. Various organic matrix modifiers were studied by Guevremont [116] for this analysis. He found citric acid to be somewhat preferable to EDTA, aspartic acid, lactic acid, and histidine. The method of standard additions was required. The standard deviation was better than 0.01 pg/1 in a seawater sample containing 0.07 pg/1. Generally, he charred at 300 °C and atomised at 1500 °C. This method required compromise between char and atomisation temperatures, sensitivity, heating rates, and so on, but the analytical results seemed precise and accurate. Nitrate added as sodium nitrate delayed the cadmium peak and suppressed the cadmium signal. 

A logical approach which serves to minimise such uncertainties is the use of a number of distinctly different analytical methods for the determination of each analyte wherein none of the methods would be expected to suffer identical interferences. In this manner, any correspondence observed between the results of different methods implies that a reliable estimate of the true value for the analyte concentration in the sample has been obtained. To this end Sturgeon et al. [21] carried out the analysis of coastal seawater for the above elements using isotope dilution spark source mass spectrometry. GFA-AS, and ICP-ES following trace metal separation-preconcentration (using ion exchange and chelation-solvent extraction), and direct analysis by GFA-AS. These workers discuss analytical advantages inherent in such an approach. 

Table 6.1 shows the results obtained by Sturgeon et al. [21] for a stored coastal water sample. The mean concentrations and standard deviations of replicates (after rejection of outliers on the basis of a simple c test-function) are given for each method of analysis. Each mean reflects the result of four or more separate determinations by the indicated method [21 ]. 

Sturgeon, C. and McAllister, E. 1998. Analysis of hCG clinical applications and assay requirements. Annals of Clinical Biochemistry 35, 460-491. 

Mester, Z. and Sturgeon, R. (eds.) (2003). Sample Preparation for Trace Element Analysis. Amsterdam, Elsevier. 

H. Matusiewicz, R.E. Sturgeon, S.S. Berman, Trace element analysis of biological material following pressure digestion with nitric acid-hydrogen peroxide and micro-wave heating, J. Anal. At. Spectrom. 4 (1989) 323-327. 

The certification procedure for seven trace metals (Ba, Ca, Li, Mg, Mn, Na and Sr) in the certified reference material FEBS-1 (National Research Council Canada, Institute for National Measurement Standards, Ottawa, Canada) based on fish otolith matrix by isotope dilution - ICP-MS in comparison to ICP optical emission spectrometry and X-ray fluorescence analysis, is described by Sturgeon et al4X The isotope dilution technique is also employed for species analysis in biological systems,46 e.g., for the determination of mercury species in tuna material,54 or in aquatic systems using cold vapour ICP-MS.55... 

Detailed analysis of IADN results show intracies in the measured concentrations of PAHs. Particle phase PAH concentrations at Sturgeon Point were higher than at other IADN master stations, especially when winds blew from Buffalo, NY [33]. Likewise, elevated particle phase PAH concentrations were observed at Brule River, Wis, a small city 40 km southwest of Duluth, MN exhibited as compared with Eagle Harbor, MI [35]. Buehler and Hites [122] suggest that this indicates that even a small urban center can cause an increase in atmospheric concentrations. 

R. G. L. Silva, S. N. Willie, R. E. Sturgeon, R. E. Santelli, S. M. Sella, Alkaline solubilization of biological materials for trace element analysis by electrothermal atomic absorption spectrometry, Analyst, 124 (1999), 1843D1846. 

Matusiewicz, H., Sturgeon, R.E. Present status of microwave sample dissolution an decomposition for elemental analysis. Prog. Analyt. Spectrosc. 12, 21-39 (1989)... 

Nakashima, S., Sturgeon, R.E., Willie, S.N., Berman, S.S. Acid digestion of marine samples for trace element analysis using microwave heating. Analyst 113, 159-163 (1988)... 

Luque de Castro, M.D., Luque Garcia, J.L. Automation of sample preparation. In Mester, Z., Sturgeon, R. (eds.) Sample Preparation for Trace Element Analysis, pp. 649-680. Elsevier, Amsterdam (2003)... 

Quevauviller Ph., 2004a. In Z. Mester, B. Sturgeon (Eds.), Sample Preparation for Trace Analysis, Elsevier, Amsterdam. 

Doyon, C., S. Boileau, R. Fortin and P. Spear. Rapid HPLC analysis of retinoids and dehydroretinoids stored in fish fiver comparison of two lake sturgeon populations. J. Fish Biol. 53 973-986, 1998. 

Ihnat M (2003) Sample preparation for food analysis. In Mester Z and Sturgeon RE, eds. Sample... 

Matusiewicz H, Sturgeon RE and Berman SS (1989) Trace element analysis ofbiolog.cal material following pressure digestion with nitric acid-hydro-gen peroxide and microwave heating. J Anal Atom Spectrom 4 323-327. 

A number of biological reference materials for trace element analysis are now available to interested laboratories. An overview on those materials is given in some recent publications Berman and Sturgeon (1987), Christensen et al. (1987), Parr et al. (1987), Rasberry (1987). 

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