Reversed Phase Column HPLC-ICP-MS Conditions for Arsenic Speciation Analysis of Rice Flour

Abstract

New measurement conditions for arsenic speciation analysis of rice flour were developed using HPLC-ICP-MS equipped with a reversed phase ODS column. Eight arsenic species, namely, arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMAA), dimethylarsinic acid (DMAA), trimethylarsine oxide (TMAO), tetramethylarsonium (TeMA), arsenobetaine (AsB) and arsenocholine (AsC), were separated and determined under the proposed conditions. In particular, As(III) and MMAA and DMAA and AsB were completely separated using a newly proposed eluent containing ammonium dihydrogen phosphate. Importantly, the sensitivity changes, in particular those of As(V) and As(III) caused by coexisting elements and by complex matrix composition, which had been problematical in previously reported methods, were eliminated. The new eluent can be applied to C8, C18 and C30 ODS columns with the same effectiveness and with excellent repeatability. The proposed analytical method was successfully applied to extracts of rice flour certified reference materials.

A rapid monitoring method for inorganic arsenic in rice flour using reversed phase-high performance liquid chromatography-inductively coupled plasma mass spectrometry

“…Buffers and chelating agents are effective for suppressing peak tailings. [28] A series of eluents containing 1 to 5 mmol L -1 of diammonium hydrogen phosphate / 0.05 % methanol was tested; the pH of the eluents was adjusted to 2.0 with HNO 3 . The eluents containing diammonium hydrogen phosphate reduced the tailing of the peaks, and improved the separation capacity.…”

Combination of isotope dilution with liquid chromatography-inductively coupled plasma mass spectrometry for the simultaneous monitoring and evaluation of cadmium and inorganic arsenic in polished rice

“…5 Although As is distributed as a various chemical species in environmental samples, As(III), As(V), dimethylarsinic acid (DMA), and monomethylarsonic acid (MMA) are observed in rice. [6][7][8][9][10][11][12] Arsenic exerts various effects on the human body depending on its chemical form, and As(III) exhibits the most toxicity among them although the toxicities of organic As species are lower. Therefore, the ML was set for i-As but not for organic As species.…”

Fast Determination of Toxic Arsenic Species in Food Samples Using Narrow-bore High-Performance Liquid-Chromatography Inductively Coupled Plasma Mass Spectrometry

“…[7][8][9][10] Therefore, arsenic speciation analysis of rice and seafood is greatly needed for risk assessment and food safety control, thus requiring fast, sensitive and reliable analytical methods, capable of separating and measuring individual arsenic species. 11 Nowadays, the coupling of high-performance liquid chromatography (HPLC) to inductively coupled plasma mass spectrometry (ICP-MS) is the most commonly used technique for the speciation analysis of arsenic; it has been widely applied to determine inorganic and organic arsenic species in rice products, [13][14][15][16][17][18] wine, 19 seafood, 20-24 fruits 25 and cereal-based food. 26 Despite these successful applications, the use of HPLC-ICP-MS for the routine arsenic speciation analysis of food samples still presents some limitations.…”