Application of co-electroosmotic capillary electrophoresis for the determination of inorganic anions and carboxylic acids in soil and plant extract with direct UV detection

Abstract

SummaryIndirect UV detection in capillary zone electrophoresis (CZE) is frequently used for the determination of inorganic anions and carboxylic acids. However, there are few reports on direct UV detection of these solutes in real samples. This paper describes the use of direct UV detection of inorganic anions and organic acids in environmental samples using co-electroosmotic capillary zone electrophoresis (co-CZE) at 185 nm. The best separation and detection of the solutes was achieved using a fused silica capillarywith an electrolyte containing 25 mM phosphate, 0.5 mM tetradecyltrimethylammonium bromide (gAB) and 15% acetonitrile (v/v) at pH 6.0. Four common inorganic anions (CI-, NO2-, NO3-and SO42-) and 11 organic acids (oxalic, formic, fumaric, tartaric, malonic, malic, citric, succinic, maleic, acetic, and lactic acid), were determined simultaneously in 15 min. Linear calibration plots for the test solutes were obtained in the range 0.02 -0.5 mM with detection limits ranging from 1 -9 I~M depending on the analyte. The proposed method was successfully used to determine inorganic anions and carboxylic acids in soil and plant tissue extracts with direct injection of the sample.

Separation of perfluorocarboxylic acids using capillary electrophoresis with UV detection

“…It results in the decrease of EOF and alleviates the adsorption on the capillary walls. This has been applied in CE determinations of various carboxylic acids in phosphate BGE to which 15 [24] to 30% [21] acetonitrile was added, for the determination of dicarboxylic acids with 40% ethanol added [21], and for fatty acids with ammonium acetate buffer and 50% acetonitrile added [28]. Determinations of anionic surfactants required 50% methanol in BGE [23], whereas determinations of fatty acids with BGEs containing trimethoxybenzoic acid and dipentylamine with addition of 85% acetonitrile and 5% dioxane were reported [30].…”

Recent advances and trends in capillary electrophoresis of inorganic ions

“…Figure 9 shows a representative set of electropherograms for metal ions differently associated with urban particulate matter, obtained after three-stage sequential extraction of a standard reference material. New procedures for determining common anions in drink- ing [180,181], rain [180], tap [47,55,98,115], mineral [47,55,98,115], river [55,98,142,180,182], groundwater [183], seawater [120,121,162,164,184], waste water [185], and soil extracts [186] or oxoanions in river water [187] were reported. Similar aquatic samples analyzed for alkali and alkaline earth metal ions encompass tap [188], rain [189], river [190], natural [191], underground water [192] and soil extracts [191,193], while transition metals were quantitatively characterized in mineral water [194], river water [133,190], and soil samples [193].…”

“…More specifically, summaries of practical contributions in which the application format of CE was miniaturized down to a single-cell level [199] and metal ions of clinical significance were involved [200] have recently become available. The most recent real-world application reports, incorporating robust sample preparation procedures, addressed the determination of common alkali, alkaline earth metal, and ammonium ions in urine [201], human plaque fluid [202], and infusion solutions [57], potassium and other cations in vitreous humor [203,204], K, Na, Mg, Ca in lettuce [205], monitoring of the releasing rates of inorganic cations and anions from pine needles [206], the quantification of anions in saliva [163], thiocyanate in different biofluids [207], measuring the nitrate level in various tissue homogenates [208] and concentrations of Cl , SO 4 2-in plant tissue extracts [186] or from microbial fermentation process liquids [209]. Also, the content of iron or zinc dithiocarbamate fungicides in wheat grains [135,210] and of different metal chelates of nitrilotriacetic acid and EDTA in complex nutrient media [211] can be quantified using CE.…”

Analysis of choline and atropine in hairy root cultures of Cannabis sativa L. by capillary electrophoresis‐electrospray mass spectrometry

“…Several chromatographic methods, including TLC [19], GC [20] and HPLC [21] as well as combined techniques such as GC-MS [21,22] and HPLC-MS [23] have been developed for the analysis of Cannabis components. The higher efficiency, accuracy, and resolution and a shorter analysis time of CE make it a powerful alternative to chromatographic separations for the analysis of plant extracts [24][25][26][27][28]. However, one of the main limitations of CE with oncolumn UV detection is its relatively low sensitivity due to the short path length.…”