HIGH PERFORMANCE LIQUID CHROMATOGRAPHY ONLINE/OFFLINE HYPHENATED TECHNIQUES: APPLICATION TO THE SPECIATION ANALYSIS OF CHROMIUM - A REVIEW

Abstract

Researchers have established that the physiological effect of metals in biological systems depend largely on the specie of the metals and not on total concentration. Thus, prioritizing chemical speciation analysis over total concentration of analytes in the monitoring metal species/toxicity) trend in modern research in metal analysis. The recent interest in chromium speciation analysis, despite its numerous industrial applications, is kindled by the established physiological effects of Cr(III) and Cr(VI), which represents the “good” and the “bad” sides of the element respectively. Consequently, the sensitivity of detectors and the efficiency of separation processes, influence the quality of analytical results of chromium speciation analysis. This review focuses on the HPLC hyphenated systems and techniques developed for the speciation analysis of chromium in the last few decades. From this review, speciation analysis of chromium was carried out in biological, environmental and food samples. Most research focus on environmental samples. The HPLC-ICP-MS system was preferred for the speciation analysis. Derivatization was employed prior to preconcentration and HPLC separation process. One of the challenges in hyphenation is observed where the detector in ICP-MS especially in situations where organic solvents are involved due to the formation of argon carbide which interfere with analytical result through matrix effect. There seems to be prospect in the online hyphenation to flame atomic absorption spectrometer (FAAS). This is useful in cases where organic solvents are required as eluents or sample preparation