Separation and preconcentration methods

Minczewski, J., Chwastowska, J., Dybczyhski, R. Separation and Preconcentration Methods in Inorganic Trace Analysis. E. Horwood, Chichester (1982)... 

In the book, much attention has been paid to separation and preconcentration methods, since they play an essential role in increasing the selectivity and sensitivity of spectrophotometric methods. The separation and preconcentration methods have been utilised also in other determination techniques. 

Chapters 1-4 provide the characteristics of the separation and preconcentration methods solvent extraction, flotation, coprecipitation with collectors, volatilization, ion exchange etc. These chapters deal also with the fundamentals of spectrophotometry, spectrophotometric methods of analysis, and most important chromogenic reagents. Chapters 5-57 have been devoted to individual elements or groups of related elements. 

The present Section provides a discussion of the following separation and preconcentration methods solvent extraction, precipitation and co-precipitation with collectors, volatilization, and methods based on the use of ion-exchangers and other sorbents. These methods are used not only with spectrophotometry, but also in conjunction with other methods of determination. 

Several separation and preconcentration methods for analysis of 3-MH, 3-MHA, and 4-MP, were reported (Tominaga et al., 1998 Schneider et al, 2003 Mateo-Vivaracho et al., 2007). Recently, HS-SPME-GC/MS method with limits of quantification (LOQs) of a dozen ng/L (close to the sensory thresholds of 3-MH and 3-MHA) was proposed (Fedrizzi et al., 2007b). This method does not include determination of 4-MP because the sensory threshold of this compound in wines ( 0.4 ng/L) is too low. The method has to be calibrated using a white wine pretreated with charcoal, corrected to a total S02 100 g/L, and spiked with different quantities of standard solutions. The optimized HS-SPME conditions (temperature, sampling time, solution pH) are reported in Table 5.6. 

Minczewski J., Chwastowska J., Dybcz3mski R. Separation and preconcentration methods in inorganic trace analysis. Chichester John Wiley Sons 1982. 

Park Ch., Chung J.S., Cha K.W. Separation and preconcentration method for palladium, platinum and gold from some heavy metals using Amberlite IRC 718 chelating resin. Bulletin of the Korean Chemical Society 2000 21 121-124. 

The fire-assay method described above has some advantages as the separation and preconcentration method of precious metals. It is useful where large samples are required owing to their extremely low... 

Highlights The main interest in studies of uranium content in oceans or seawater is to determine the effect of anthropogenic activities. Therefore, the presence and abundance of the minor isotopes, particularly U, must be accurately determined, and this requires preconcentration and separation of the uranium and the use of accelerator mass spectrometry (AMS) for the analysis. Other mass spectrometric techniques (ICPMS or TIMS) can also be used but with inferior performance. The high salinity of ocean water introduces a matrix effect that could bias ICPMS measurements of the uranium content, so the separation and preconcentration methods described earlier may be needed for precise quantification of uranium (an internal standard can also be used for this purpose). 

J. Minczewski, J. Chwasstowska. R. Dybczinski Separation and Preconcentration Methods, in Inorganic Trace Analy.si.s, Ellis Horwood Ltd., Chichester 1982. 

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