A Review On Colorimetric Method For Quantification Of Vitamin B12

Abstract

Vitamin B12 (cobalamin) is a crucial water-soluble vitamin essential for numerous biological processes including DNA synthesis, red blood cell formation, and neurological function. The quantification of vitamin B12 has significant clinical and pharmaceutical importance due to the widespread prevalence of deficiency disorders. This review examines the current state of colorimetric methods for vitamin B12 quantification, focusing on cobalt-based detection approaches. The paper analyzes various colorimetric techniques including nitroso-salt complexation (1), spectrophotometric methods using complexing agents (2), and recent advances in optical detection systems (3). Traditional methods rely on the decomposition of vitamin B12 to liberate cobalt ions, which are then complexed with chromogenic reagents such as Nitroso-R-salt to produce measurable colored complexes with maximum absorption at 435 nm (4). Emerging approaches include carbon dot nanosensors (5), fluorescent probes (6), and electrochemical sensors with enhanced sensitivity and selectivity (7). The review highlights that colorimetric methods offer practical advantages including cost-effectiveness, simplicity, and suitability for on-site testing compared to conventional HPLC and mass spectrometry techniques (8). However, challenges remain in terms of interference from other metal ions and the need for sample pretreatment. Recent developments in nanotechnology-based colorimetric sensors show promise for improved specificity and lower detection limits (9). The paper concludes that colorimetric methods continue to be valuable tools for vitamin B12 quantification, particularly in resource-limited settings, with ongoing innovations enhancing their analytical performance.