Fluoride derivatization technique

In 1999, Wagner et al. [61] developed another derivatization technique for the analysis of bromate, which can be directly combined with the US EPA Method 300.1 [62], In Part A, Method 300.1 describes the separation of the seven standard anions bromide, chloride, fluoride, nitrite, nitrate, orthophosphate, and sulfate, and in Part B the separation of bromate, bromide, chloride, and chlorite on an lonPac AS9-HC high-capacity anion exchanger. The technique developed by Wagner et al. is based on the reaction of bromate with o-dianisidine (ODA) in an acidic solution [63,64] with subsequent photometry of the reaction product at 540 nm. 

The spot synthesis technique is simple and easily accessible for practical use. There are some limitations to the scope of chemistries that can be used with cellulose as a solid support. To eliminate some of these shortcomings, Gao and EsnoufP° 4 proposed using a different membrane, Immobilon AV-1, for spot synthesis. Before the synthesis of peptide arrays can be carried out, this polyvinylidene fluoride based material is derivatized with ethane-1,2-diamine, followed by coupling of Fmoc-(3Ala as a spacer. In most other aspects, this peptide array synthesis is very similar to the spot synthesis proposed by Frank.t l... 

GC with Bourier transform infrared spectroscopy (BUR) has been used for determination of chlorophenols in drinking water [95]. Before the GC-BUR analysis, the phenols were acetylated with acetic anhydride followed by off-line SPB using graphitized carbon cartridge. GC with microwave-induced plasma atomic emission spectroscopy was used in combination with two different off-line SPB procedures [96]. Derivatization with 3,5-bis(trifluoromethyl)benzyldimethylphenylammonium fluoride in combination with MS detection in negative chemical ion mode has been used for the determination of chlorophenols in industrial wastewater [94]. As seen earlier, SPB sample preparation is a commonly integrated part of the overall system setup in GC analysis. The technique is treated in more detail in the following section. 

Due to the fact that, especially in the first moments of oxidation, the amounts of oxygen containing groups or products is very low, their identification by the above-mentioned methods is difficult. For detailed studies, Carlsson et al. [116] proposed FTIR techniques of great sensitivity, recorded after some derivatization reactions these have been accomplished by means of phosgene and iodine to convert hydroperoxides to other compounds, diazomethane to convert acids and peracids to methyl esters, sulfur tetrafluoride to convert acid to acid fluorides, or nitric oxides to convert alcohols and hydroperoxides to nitrites and nitrates. 

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