A novel spectrophotometric method for determination of histamine based on its complex reaction with Cu(II) and alizarin red S

An analytical method of histamine determination by UV-Vis spectrophotometry in presence of Cu(II) and alizarin red S (ARS) is developed. It is based on the ability of Cu(II) and alizarin red S to form color complex compound with histamine. Absorbance is measured at a maximum wavelength of 505.5 nm. Optimization of the concentrations of Cu(II) and alizarin red S, as well as pH in view of the method's response time is carried out. The results obtained show that the best response time of 10 min is obtained in case the concentrations of Cu(II) and alizarin red S equal to 50 ppm, while pH is 6. The analytical characteristics of the method refer to the coefficient of variation, the detection limit, and the limit of quantitation have values of 0.650 %, 8.94 ppm, and 29.82 ppm, respectively. They are obtained with a sensitivity of 0.0054 ppm^-1 and linearity of 0.99. The accuracy of determination when histamine is present at a concentration of 50 ppm, 100 ppm, and 150 ppm is 105.70 %, 105.06 %, 94.12 %, correspondingly.