Fast separations by capillary electrophoresis hyphenated to electrospray ionization time-of-flight mass spectrometry as a tool for arsenic speciation analysis

Abstract

Fast capillary electrophoresis (CE) hyphenated to time-of-flight mass spectrometry (TOF-MS) of four organoarsenic species (glycerol oxoarsenosugar, sulfate oxoarsenosugar, arsenobetaine, arsenocholine) are presented using short length CE capillaries under high electric field strengths of up to 1.3 kV cm À1 with small inner diameter (ID). The separation of arsenosugars by CE is demonstrated for the first time. An aqueous formic acid solution was employed as the background electrolyte (BGE) for the separation. Various acid concentrations were evaluated for their influence on migration times, separation efficiency as well as with regard to controlling the charge of the arsenic species. A 0.1 M formic acid/ammonium formate buffer (pH 2.8) proved to be suitable for the separation of the four species. A non-aqueous BGE was tested as an alternative buffer system for fast speciation analysis. Separation of arsenobetaine and arsenocholine could even be achieved within 10 s by pressure-assisted CE. Application of the optimized method for the analysis of extracts of a seagrass and a Wakame algae sample as well as the brown algae homogenate reference material IAEA-140/TM revealed a clear signal for the glycerol arsenosugar.

Recent advances in the combination of capillary electrophoresis with mass spectrometry: From element to single‐cell analysis

“…The method was characterized with linear oligosaccharides and used to monitor the enzymatic hydrolysis of maltooligosaccharides with α‐amyloglucosidase. A fast CE‐ESI‐MS analysis of four organoarsenic species, glycerol oxoarsenosugar, sulfate oxoarsenosugar, arsenobetaine, and arsenocholine was demonstrated for the first time . Short capillaries filled with a 0.1 M formic acid/ammonium formate buffer (pH 2.8) under high electric field strengths of up to 1.3 kV/cm proved to be suitable for the separation of the four species.…”

Ionic liquid based carrier mediated hollow fiber liquid liquid liquid microextraction combined with HPLC-ICP-MS for the speciation of phenylarsenic compounds in chicken and feed samples

“…4 The most commonly used separation technique is high performance liquid chromatography (HPLC), 1,5,6 while gas chromatography (GC) 7 and capillary electrophoresis (CE) 8 are less used because GC requires a derivatization step to convert non-volatile arsenic compounds into their volatile derivatives prior to the separation 9 and CE lacks sensitivity and selectivity for realworld samples with a complex matrix. 4 The most commonly used separation technique is high performance liquid chromatography (HPLC), 1,5,6 while gas chromatography (GC) 7 and capillary electrophoresis (CE) 8 are less used because GC requires a derivatization step to convert non-volatile arsenic compounds into their volatile derivatives prior to the separation 9 and CE lacks sensitivity and selectivity for realworld samples with a complex matrix.…”

Inorganic Arsenic Determination in Food: A Review of Analytical Proposals and Quality Assessment Over the Last Six Years

“…Niegel et al 216 develop a method based on CE coupled to electrospray ionization time-of-flight mass spectrometry (CE-ESI-TOF-MS) for arsenic speciation, with application to the analysis of some algae extracts; although no results for iAs compounds are obtained. Liu et al 217 propose a novel interface (the commercial CE-ESI-MS sprayer kit) for CE-ICP-MS, and apply it to arsenic speciation in the CRMs TORT-2 and DORM-3, as well as to herbal plants and chicken meat, the results from which include iAs compounds.…”