Photometric detection at 405 nm in trace analysis by capillary isotachophoresis

Application of isotachophoresis in food analysis

“…The trick of the developed method consists in derivatization of amino acids with the anhydride of citraconic acid followed by the separation of the negatively charged products at pH 6. Kaniansky and co-workers [65] developed a method for the determination of 2,4-dinitrophenyl derivatives of amino acids in wine. Using visible photometric detection at 405 nm, an LOD of 10 ±8 mol/L was reached.…”

On-line isotachophoresis. A selective sample pretreatment prior to column liquid chromatographic analysis

“…Most of these analyses concern the determination of inorganic ions [1][2][3][4][5][6][7][8][9][10][11]. Other compounds analysed are fatty acids [12], derivatives of phenol [13], alphametrine insecticides [14], triazine and quaternary cationic herbicides [15,16]. Several publications report the use of ITP as a preparative technique or as a sample pretreatment method.…”

Separation of multicomponent mixtures of 2,4-dinitrophenyl labelled amino acids and their enantiomers by capillary zone electrophoresis

“…The CE separations of DNP-AAs are dealt with in several papers (see, e.g., [8, 14±21]). Our interest in the CE separations of these AA derivatives dates back to our previous studies dealing with ITP-CZE separations [21] and ITP trace analysis [14]. CE separabalities of their enantiomers were already demonstrated in the works by several authors [15,16,19,20].…”

“…2,4-Dinitrofluorobenzene (DNFB) is one of the oldest derivatization agents in the field of AA analysis [13]. This agent provides for both primary and secondary AAs chemically, and, when appropriate measures are taken [14], also photochemically stable 2,4-dinitrophenyl labeled derivatives (DNP-AAS). The CE separations of DNP-AAs are dealt with in several papers (see, e.g., [8, 14±21]).…”