“…Numerous analytical techniques including inductively coupled plasma-atomic emission spectrometry (ICP-AES), 4,[6][7][8] ame atomic absorption spectrometry (FAAS), 1,9,10 inductively coupled plasma-mass spectrometry (ICP-MS), 11,12 ultraviolet visible absorption spectrometry (UV-vis), 13 high performance liquid phase chromatography (HPLC), 14 gas chromatography (GC), 15,16 inductively coupled plasma optical emission spectrometry (ICP-OES), 17 spectrouorimetry spectrophotometry, 18 and total reection X-ray spectrometry (TXRF) 19 have been reported for Cr determination. In spite of the advancement in modern analytical instruments, complications exist with direct determination of analytes at trace and ultra-trace levels.…”