Determination of Glycarbylamide Based on Formation of Nickel Chelate

Abstract

A new and simple analytical method for glycarbylamide (GB) based on the formation of nickel chelate was developed. The proposed method is as follows: sample solution is mixed with 0.08 mmol/L nickel nitrate in 0.2 mol/L carbonate buffer (pH 9.0), and the absorbance is measured at 290 nm. Under the optimal conditions, GB could be determined in the concentration range from 0.13 μg/mL to 2.6 μg/mL (r=0.9999). Using this method for HPLC post column reaction, GB levels in chicken liver extracts could be determined. The recovery of GB was 79.4% (RSD=2.6%, n=3) and the quantitation limit was 30 ng/g. The apparent molar extinction coefficient (ε) of the GB-nickel complex was 8.5×10³. The molar ratio of the complex is GB : nickel ion=2 : 1.