Simultaneous analysis of Cr(III), Cr(VI), and chromium picolinate in foods using capillary electrophoresis‐inductively coupled plasma mass spectrometry

Abstract

We herein reported a method for the simultaneous detection of trace Cr(VI), Cr(III), and chromium(III) picolinate (CrPic) in foods using CE-ICP-MS together with ultrasonic-assisted extraction. The Cr(III) (Cr(3+) ) was chelated with trans-1,2-diaminocyclohexane-N,N,N´,N´-tetraacetic acid (DCTA) to form a single charged Cr-DCTA(-) complex. Then, Cr(VI) (CrO4 (2-) ), Cr-DCTA(-) , and CrPic were separated by CE within 8 min under a separation voltage of -13 KV followed by their monitoring with ICP mass spectrometer (ICP-MS). The proposed method is simple, effective, and sensitive. It has an instrument detection limit of 0.10, 0.18, and 0.20 ngCr/mL for Cr(VI), Cr(III), and CrPic, respectively. With the help of the methods, we have successfully determined Cr(VI), Cr(III), and CrPic in nutritional supplement (CrPic yeast tablet) with an RSD (n = 5) <6% and a recovery of 93-103%. The experimental results showed that CrPic was the main speciation of chromium in the nutritional supplement, with a concentration of 1514.6 μg Cr/g.

Recent advances in CE‐MS coupling: Instrumentation, methodology, and applications

“…Microwave‐assisted extraction was used for analysis of trace lead compounds from marine animals as Pb 2+ , trimethyl, and triethyl lead chloride to reach a detection limit as low as 0.012–0.084 ng Pb/mL. Ultrasonic assisted extraction for a simultaneous detection of trace Cr(VI), Cr(III), and chromium(III) picolinate in a nutritional supplement enabled a LOD of 0.10–0.20 ng Cr/mL . And field‐amplified sample stacking injection into electrophoretic capillary led to a development of sensitive ultratrace method for the simultaneous analysis of methylmercury, ethylmercury, and Hg 2+ in water samples with LOQs of 0.26–0.45 pg/mL .…”

“…CE methods were developed for contactless conductivity, fluorescence, UV, and MS detection. The authors declare the systems with contactless conductivity and fluorescence detection superior to UV and MS. As already mentioned, CE‐ICP‐MS was used for the speciation of trace amounts of lead in marine animals , chromium in a nutritional supplement , arsenic in rice , and ultratrace amounts of mercury in water samples . Acunha et al.…”

Iminodiacetic acid functionalized magnetic nanoparticles for speciation of Cr(iii) and Cr(vi) followed by graphite furnace atomic absorption spectrometry detection

“…Among these elemental detection techniques, GFAAS has the advantages of high sensitivity, low cost, low sample consumption, and is suitable to single elemental analysis at trace level. 11 The separation techniques used for Cr speciation include chromatographic approaches such as liquid chromatography, 12 ion chromatography 13 and capillary electrophoresis 14 and non-chromatographic separation technologies such as coprecipitation, 15 ion exchange, 16 liquid phase microextraction, 17 cloud point extraction 18 and solid phase extraction (SPE). 19 For a simple elemental speciation, especially for a different valence state of Cr, SPE is the most commonly used separation technique, featuring with high separation efficiency, high enrichment factors, low consumption of organic solvent, exibility and plenty of sorbents available.…”

Simultaneous detection of zinc dimethyldithiocarbamate and zinc ethylenebisdithiocarbamate in cabbage leaves by capillary electrophoresis with inductively coupled plasma mass spectrometry

“…Inductively coupled plasma mass spectrometry (ICP‐MS), which is widely used for the determination of trace metals , possesses several inherent advantages including extremely high sensitivity for most metallic ions, wide linear dynamic range, high speed analysis, excellent mass resolution for metallic ions, and the ability to perform isotopic analysis . Therefore, the coupling of CE and ICP‐MS becomes a powerful tool for elemental speciation analysis, and has been used in the speciation analysis of some elements such as arsenic , selenium , lead , mercury , and chromium . To the best of our knowledge, the method of simultaneous analysis of Ziram and Zineb using CE–ICP‐MS has not been reported so far.…”