Speciation Analysis of Arsenic Compounds by High-Performance Liquid Chromatography in Combination with Inductively Coupled Plasma Dynamic Reaction Cell Quadrupole Mass Spectrometry: Application for Vietnamese Rice Samples

Abstract

In this work, high-performance liquid chromatography in combination with inductively coupled plasma dynamic reaction cell quadrupole mass spectrometry was introduced and optimized for speciation analysis of five major arsenic species including arsenobetain (AsB), arsenite (As(III)), monomethylarsonic (MMA), dimethylarsenonic acid (DMA), and arsenate (As(V)) in rice samples. Five arsenic compounds were separated on a Hamilton PRP X100 strong anion-exchange column employed with the mobile phase that is compatible with mass spectrometry, containing ammonium carbonate, methanol, and disodium ethylenediaminetetraacetic acid. Arsenic compounds were detected online by inductively coupled plasma dynamic reaction cell quadrupole mass spectrometry utilizing oxygen as the reaction gas at a flow rate of 0.7 mL·min−1. Five selected arsenic species were baseline separated at the optimum experimental conditions. The excellent LOD and LOQ values of the developed method were achieved in the range of 0.5 to 2.9 μg·kg−1 and 1.7 to 9.6 μg·kg−1 for all species of arsenic, respectively. The ionization effect in plasma during chromatographic gradient elution was systematically investigated by using postcolumn injector. Arsenic compounds in rice samples were extracted by diluted nitric acid at elevated temperature. The extraction efficiency and the interconversion of target compounds during sample preparation were also assessed. The full validation of the developed method was performed by using certified reference material, BRC 211, from European Institute of Reference and Standard for speciation analysis. The recovery of all selected arsenic species was in the range of 70 to 135.5%. The validated method was also applied to analyze rice samples collected from some contaminated rice fields. The results showed that As(III), DMA, and As(V) were found in all rice samples. Average concentration (range) of inorganic arsenic and DMA in all rice samples were 130.3 (65.5–228.1) and 32 (8.2–133.01) μg·kg−1, respectively. However, total concentration of inorganic arsenic in most of investigated rice samples was below the maximum residual level according to US-FDA and European Union standards.

Antioxidant activity of selenium-enriched Chrysomyia megacephala (Fabricius) larvae powder and its impact on intestinal microflora in D-galactose induced aging mice

“…Compositions of SCML including protein, crude fat and moisture content were analyzed according to method GB5009-2016 of China National Food Safety Standard. Se content was detected by Inductively Coupled Plasma (ICP) according to Vu et al with minor modifications [25]. The results are shown in Table 1.…”

Arsenic and Heavy Metals in Vietnamese Rice: Assessment of Human Exposure to These Elements through Rice Consumption

“…To date, many analytical methods like flame atomic absorption spectrometry (F-AAS) [ 8 ], graphite furnace atomic absorption spectrometry (GF-AAS) [ 9 , 10 ], hydride generation atomic absorption spectrometry (HG-AAS) [ 11 – 13 ], and inductively coupled plasma optical emission spectrometry (ICP-OES) [ 14 , 15 ] have been developed for analysis of heavy metals in the food matrices, especially in rice samples. Some speciation analysis methods have been also developed for analysis of toxic compounds, especially arsenic compounds, in rice samples [ 16 – 20 ]. However, inductively coupled plasma-dynamic reaction cell-quadrupole mass spectrometry (ICP-DRC-QMS) has become a golden standard for multielement analysis because of sensitivity, selectivity, wide dynamic linearity range, and isotopic analysis ability [ 21 ].…”

Metal-Organic Framework MIL-53(Fe): Synthesis, Electrochemical Characterization, and Application in Development of a Novel and Sensitive Electrochemical Sensor for Detection of Cadmium Ions in Aqueous Solutions

“…Determining the concentration of pollutants is an important step in environmental monitoring and supervision and is a basis for offering solutions to protect the environment. Chromatography and its associated techniques such as atomic emission spectroscopy (AES), atomic fluorescence spectroscopy (AFS), atomic absorption spectroscopy, and inductively coupled plasma mass spectrometry are common and effective methods for identifying environmental contaminants [3,4]. However, the above techniques showed many disadvantages such as long testing times, expensive equipment, and complex measurement processes [3,5].…”