Study On The New Method For The Determination Of Pharmaceuticals By Flow Injection Analysis Coupled To Resonance Rayleigh Scattering Detector

Because of the connection of the high sensitivity of resonance Reyleigh scattering with the high precision of flow injection analysis, the technique that flow injection analysis coupled to resonance Reyleigh scattering detector can not only speed up the analysis to realize the automatization of RRS, but also can enhance the sensitivity and precision of the analysis results. So it has very important significance to study and develop the application of FIA-RRS method in analytical chemistry. The FIA-RRS method was developed to determinate Diphenhydramine Hydrochloride, Verapamil Hydrochloride, Propafenone Hydrochloride, some local anesthetics and Meclofenoxate Hydrochloride in this paper.1 12-Tungstophosphorie acid- Diphenhydramine Hydrochloride systemsIn acidic medium, 12-Tungstophosphoric Acid reacts with Diphenhydramine Hydrochloride to form complexes, which results in great enhancement of resonance rayleigh scattering (RRS). The maximum RRS peak was located at 340 nm, RRS intensity is proportional to the concentration of diphenhydramine hydrochloride in the range of 1.0-9.0μg/mL. Therefore, a new method for the determination of diphenhydramine hydrochloride by FIA-RRS was developed. The method has high sensitivity and good selectivity, and the detection limit (3σ) is 5.3 ng/mL. The method had been applied to determining the content of DP·HCl in urine samples, and the recovery was between 96.0％and 104.2％. The reaction condition was investigated, and the reasons for enhancement of RRS were discussed by AM1 of quantum chemistry.2 12-Tungstophosphoric acid-Verapamil Hydroehloride systemsIn pH 1.0 acidic medium, 12-Tungstophosphoric acid (TP) reacted with VP to form an ion-associate complex, which resulted in a significant enhancement of RRS intensity and appearance of new RRS spectra. The maximum scattering peak was located at 293 nm, RRS intensity was proportional to the concentration of VP in the range of 0.017-13.0μg/mL, and the detection limit (3σ) was 5.1 ng/mL. The proposed method exhibits the satisfactory reproducibility with a relative standard derivation (R.S.D.) of 2.1％for 11 successive determinations of 5.0μg/mL VP. Therefore, a novel method for the determination of VP by FIA-RRS was developed. The optimum reaction conditions and the parameters of the FIA operation as flow rate, injection volume, reactor length and others had been optimized in this paper. The effects of coexisting substances and analytical application were investigated, and the results showed that the method had good selectivity and reproducibility. The present method had been applied to the determination of VP in serum samples and pharmaceuticals with satisfactory results, which agreed with the method that used in the pharmacopoeia. The maximal sample throughput in the optimized system was 80 h^-1.3 12-Tungstophosphoric acid-propafenone Hydrochloride systemsA simple, sensitive and rapid flow-injection method with resonance Reyleigh scattering (FIA-RRS) was developed for the determination of propafenone (PPF). The method is based on the ion-associate complex that formed by 12-Tungstophosphoric acid (TP) and propafenone. In pH 1.0 acidic medium, TP reacted with PPF to form an ion-associate complex, which resulted in a significant enhancement of RRS intensity. The maximum scattering peak was located at 340 nm, the RRS intensity was proportional to the concentration of PPF in the range of 0.8-9.0μg/mL, and the detection limit (3σ) of 1.0 ng/mL was obtained at a sampling rate of 60 samples h^-1. The proposed method in this paper exhibits the satisfactory reproducibility with a relative standard derivation (R.S.D.) of 2.1％for 10 successive determinations of 2.0μg/mL PPF. The present method had been successfully applied to the determination of PPF in serum samples and pharmaceutical samples. The results obtained were in agreement with the method that used in the pharmacopoeia.4 12-Tungstophosphoric acid-some local anesthetics systemsIn pH 1.0 hydrochloric acid medium, 12-tungstophosphoric acid (TP) reacts with some local anesthetics such as tetracaine(YC), procaine (PC) and lidocaine (LC) to form ion-associate complexes, which results in a significant enhancement of resonance Rayleigh scattering (RRS) and appearance of new RRS spectra. Their maximum scattering peaks were located at 345 nm (TP-TC), 368 nm (TP-PC), 379 nm (TP-LC), and the RRS intensities were proportional to the concentrations of the three local anesthetics in a certain range. Therefore, a novel method for the determination of TC, PC and LC by RRS coupled with flow injection analysis (FIA) has been developed, and the detection limits (3o) were 0.5-9.5 ng/mL for different local anesthetics. Taking the TC-TP system that is highest sensitive as an example, the effects of coexisting substances and analytical application were investigated. The results showed that the method had good selectivity and reproducibility. The recovery of the present method which has been applied to the determination of TC in urine sample was 98.8-103.2％. And the relative standard derivation for 9 successive determinations of 2.0μg/mL TC was 1.7％with sampling frequency of 60 h^-1. In addition, the charge distribution of three anesthetics by quantum chemistry AM1 method was calculated, and the reaction mechanism have been discussed from the difference of the anesthetics structure.5 12-Tungstophosphoric acid- meclofenoxate Hydrochloride systemsIn pH 1.0 acidic medium, 12-Tungstophosphoric acid (TP) reacts with meclofenoxate (MFX) to form an ion-associate complex, which results in a significant enhancement of RRS intensity. The maximum scattering peak was located at 374 nm, the RRS intensity was proportional to the concentration of MFX in the range of 0.2-12.0μg/mL. Therefore, a novel method for the determination of MFX by FIA-RRS was developed. The method has high sensitivity and the detection limit (3σ) is 5.6 ng/mL. The effect of coexisting substances and the analysis application of the method were discussed, and it showed that the method had good selectivity. The present method has been applied to the determination of MFX in urine samples and MFX capsules, and the results were agreed with the method that used in the pharmacopoeia. The proposed method exhibits the satisfactory reproducibility with a relative standard derivation (R.S.D.) of 3.7％for 9 successive determinations of 4.0μg/mL MFX. The maximal sample throughput in the optimized system was 48 h^-1.