RESUMO
A highly selective and sensitive method of reversed phase high-performance liquid chromatography (RP-HPLC) coupled with resonance Rayleigh scattering (RRS) was developed for the determination of procaine, bupivacaine and tetracaine. Separation of three local anaesthetics was achieved at 35 °C on a C18 column. The mobile phase was 30: 70 (v/v) acetonitrile/triethylamine-phosphoric acid buffer (pH 2.9) at flow rate of 0.3 mL/min. The RRS detection was conducted by taking advantage of the strong RRS enhancement of the local anaesthetics with erythrosine reaction in an acidic medium. Under optimum conditions, the limit of detection (S/N = 3) values were in the range of 2.4-11.2 ng/mL. Recoveries from spiked human urine samples were 95.8%-104.5%. The proposed method applied to the determination of local anaesthetics in human urine achieved satisfactory results. In addition, the mechanism of the reaction is fully discussed. Copyright © 2016 John Wiley & Sons, Ltd.
Assuntos
Anestésicos Locais/urina , Bupivacaína/urina , Procaína/urina , Tetracaína/urina , Cromatografia Líquida de Alta Pressão , Humanos , Espalhamento de Radiação , Espectrometria de FluorescênciaRESUMO
A simple, fast, costless, sensitive and selective method of resonance light scattering coupled with HPLC was established for the determination of 6-mercaptopurine in human urine sample. In a Britton-Robinson buffer solution of pH5.5, the formation of coordination complex between 6-mercaptopurine and metal palladium (II) led to enhance the RLS intensity of the system. The RLS signal was detected by fluorescence detector at λ(ex)=λ(em)=315 nm. The analytical parameters were provided by the coupled system, the linear of 6-mercaptopurine response from 0.0615 to 2.40 µg L(-1) and the limit of detection (S/N=3) was 0.05 µg L(-1). The presented method has been applied to determine 6-mercaptopurine in human urine samples which obtained satisfactory results. Moreover, the reaction mechanism and possible reasons for enhancement of RLS were fully discussed.
Assuntos
Antimetabólitos Antineoplásicos/urina , Cromatografia Líquida de Alta Pressão/métodos , Difusão Dinâmica da Luz/métodos , Mercaptopurina/urina , Cromatografia Líquida de Alta Pressão/economia , Cromatografia Líquida de Alta Pressão/instrumentação , Difusão Dinâmica da Luz/economia , Difusão Dinâmica da Luz/instrumentação , Desenho de Equipamento , Humanos , Limite de Detecção , Modelos MolecularesRESUMO
A reliable and versatile high performance liquid chromatography coupled with resonance Rayleigh scattering method was established for the determination of three fluoroquinolones, including levofloxacin, norfloxacin and enrofloxacin in water sample and human urine sample. In pH 4.4-4.6 Britton-Robinson buffer medium, the fluoroquinolones separated by high performance liquid chromatography could react with erythrosine to form 1:1 ion-association complexes, which could make contributions to the great enhancement of RRS. The resonance Rayleigh scattering signal was recorded at λex=λem=330 nm. The resonance Rayleigh scattering spectral characteristics of the drugs and the experimental conditions such as pH, detection wavelength, erythrosine concentration, flow rate, the length of reaction tube were studied. Quantum chemistry calculation, Fourier transform infrared spectroscopy and absorption spectroscopy were used to discuss the reaction mechanism. The recoveries of samples added standard ranged from 97.53% to 102.00%, and the relative standard deviation was below 4.64%. The limit of detection (S/N=3) of 0.05-0.12 µg mL(-1) was reached, and the linear regression coefficients were all above 0.999. The proposed method was proved as a simple, low cost and high sensitivity method.
