Rank annihilation factor analysis method for kinetic-spectrophotometric measurement of morphine in unknown opiate samples mixture

Measuring the compounds in narcotic drugs, including morphine, is of great importance in medical science and forensic applications [1]. For this purpose, many analytical methods have been developed [2,3]. In chromatographic methods such as LC, GC, TLC, and HPLC, the long procedure is a result of the time-consuming analysis work and the high cost of the device, among the disadvantages of these methods. In this study, a fast, simple, and cheap kineticspectrophotometric method was used to investigate and determine the concentration of morphine in the mixture of real drug samples by using the rank annihilation factor analysis (RAFA) method. In the present work, the Marquis reagent was used as a simple and well-known reaction to obtain kinetic-spectrophotometric data of the RAFA method for morphine analyte in the mixture of morphine-heroin-codeine samples. In the first stage, the proposed method was checked with simulated data, and then two-dimensional kinetic-spectrophotometric data were recorded for the standard and mixture of unknown samples. Finally, using the RAFA method, the presence of the mentioned species in the mixture of unknown samples (morphine-heroin-codeine) was detected and its concentration was determined. The results showed that this method as an efficient, effective, and simple technique to determine the concentration of morphine in unknown samples mixture with a linear range of 6×01-7-4×01-5M has excellent performance. To evaluate and confirm the accuracy of the proposed method, the measurement of morphine in the presence of the ternary mixture of morphine-heroin-codeine in the human urine sample was investigated. The results of this investigation showed that by adding values of 3×10-5 and 4×10-6 M morphine in the mixture of morphine-heroin-codeine sample, the percentage of recovery was obtained 96.7 and 102.5%, that these results confirm the accuracy of the RAFA method to measure morphine in the mixture of real drug samples.