Determination of Cobalamin in Nutritive Supplements and Chlorella Foods by Capillary Electrophoresis−Inductively Coupled Plasma Mass Spectrometry

Abstract

A capillary electrophoresis-inductively coupled plasma mass spectrometric (CE-ICP-MS) method for the determination of cobalamin is described. Samples of cobalt-containing compounds were subjected to electrophoretic separation before injection into the microconcentric nebulizer (CEI-100) of ICP-MS. The Co-containing compounds studied include cyanocobalamin (CN-Cbl, vitamin B12), hydroxocobalamin (OH-Cbl), and Co(II). The species studied were well separated using a 70 cm lengthx75 microm i.d. fused silica capillary with the applied voltage set at +20 kV. A 25 mM Tris buffer (pH 9.0) containing 15 mM sodium dodecyl sulfate (SDS) was used as the electrophoretic buffer. The CE-ICP-MS detection limits were 0.3, 0.2, and 1.7 ng of Co mL(-1) for CN-Cbl, OH-Cbl, and Co(II), respectively. The concentrations of cobalamin compounds were determined in selected nutritive supplements and chlorella samples. A microwave-assisted extraction method was used for the extraction of these compounds. Over 92% of the total cobalt species was extracted using a 5% v/v HNO3 solution in a focused microwave field within a period of 10 min; spike recovery was in the range of 94-105% for various species. The major cobalt species in nutritive supplements and chlorella samples was cyanocobalamin.

Hydroxocobalamin Quantification in Human Plasma by High-Performance Liquid Chromatography Coupled with Electrospray Tandem Mass Spectrometry in a Pharmacokinetic Study

“…This is the first HPLC-MS-MS method developed for measuring hydroxocobalamin in human plasma. Hydroxocobalamin has been determined in human and rat plasma by isotopic dilution (LLOQ 34 pg/mL) [4,5], in nutritive supplements and chlorella foods by capillary electrophoresis-inductively coupled plasma mass spectrometry (LLOQ 200 pg/mL, run-time 11 min) [6] and in ovine tissues by 1.14 ± 0.09 2.14 ± 0.94 0.0036 Table 5: Average, SD and T-Test comparing clereance (CL) and AUClast against body surface area (BSA; m 2 ) and weight (kg).…”

“…Hydroxocobalamin has been determined in human and rat plasma by isotopic dilution [4,5], in nutritive supplements and chlorella foods by capillary electrophoresis-inductively coupled plasma mass spectrometry [6] and in ovine tissues by high-performance liquid chromatography [7]. Here we describe a fast, sensitive, and specific method for quantification of hydroxocobalamin in human plasma using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS-MS), with paracetamol as the internal standard.…”

Recent food safety and food quality applications of CE‐MS

“…This is the case of the analysis of proteins [72][73][74][75][76][77][78] and peptides [73,74], antioxidants [79][80][81][82][83][84][85][86][87][88][89][90], vitamins [91], amino acids [92], cytokinins [93,94] and other organic acids [95,96]. Moreover in the last 5 years, all the works found in the literature regarding the application of CE-MS in food quality have employed CZE as the most used CE mode.…”

Development of a Quinazoline-Based Chelating Ligand for Zinc Ion and Its Application to Validation of a Zinc-Ion-Coordinated Compound

“…On the basis of the fact that pK a of pyrithione is 4.6, Zn 2ϩ could be completely released from ZnPT in the region with acidic pH. Thus, HCl, HNO 3 , H 3 PO 4 , and H 2 SO 4 were 4 and Zn 2ϩ was thought to have enhanced the fluorescence intensity of the HBQZ-Zn 2ϩ complex. Certainly, the f value of the HBQZ-Zn 2ϩ complex in the presence of 10 mM H 3 PO 4 was 0.712, whereas the f value of the HBQZ-Zn 2ϩ complex alone was 0.349.…”

“…Metal ions can act as a Lewis acid, and due to this property, they have been artificially incorporated into drugs, pigments, or dietary supplements [1][2][3][4][5] in order to gain the intrinsic activity. Metal-ion-coordinated compounds are generally validated using atomic absorption spectrometry (AAS), because metal ions can be selectively quantified by AAS.…”