Single reagent extraction

To determine secondary alkanesulfonates in sewage wastewaters, solid phase extraction (SPE) and a single-step procedure which combines elution and injection port derivatization for analysis with GC-MS were developed [36]. Again a tetrabutylammonium ion pair reagent was employed both to elute the secondary alkanesulfonates as their ion pairs from CI8-bonded silica disks and to derivatize sulfonate ion pairs under GC injection port conditions. Secondary alkanesulfonates were effectively recovered from samples of raw sewage (>92%) and from primary (>98%) and secondary (>85%) effluents. No... 

Note Derivatization with this reagent sequence in combination with extraction and TLC separation is speciftc for amitriptyline and nortriptyline in the analysis of plasma furthermore its high sensitivity allows its employment in pharmacokinetic studies, e. g. after the oral administration of a single dose of 25 mg amitriptyline. 

This chapter considers methods of trace element speciation, and their application to soils, that involve selective chemical extraction techniques. It will be concerned firstly with extraction by single selective reagents and secondly with the development and application of sequential extraction procedures for soils and related materials. Sequential extraction procedures for sediments are discussed in depth in Chapter 11. Speciation in the soil solution and modelling aspects of its interaction with soil solid phases are comprehensively covered in Chapter 9 and will not be considered here. 

Sequential extraction involves treatment of a sample of soil or sediment with a series of reagents in order to partition the trace element content. The reagents used are generally similar to those employed as single extractants to liberate metals bound to particular components of the sample matrix, discussed above. The growth in popularity of the approach is demonstrated by the marked increase in publications in which it has featured over the past decade (Fig. 10.2). 

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