Molecular and crystal structure of trans-(dicyanato)-bis(triphenylphosphine)palladium(II)

The triphenylphosphine (PPh3) displaces the acetonitrile from [PdCl2(CH3CN)2], and subsequent addition of the potassium cyanate causes substitution of the chloro ligand by NCO- to yield trans-[Pd(NCO)2(PPh3)2]. The complex was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The title compound was crystallized in a triclinic system, space group P1 with a = 9.213(3)Å, b = 9.781(7)Å, c = 10.483(5)Å, α = 111.39(5)°, β = 93.49(3)°, γ = 103.81(4)°, V = 845.0(1)Å3, Z = 1. The coordination geometry around Pd(II) in this complex is nearly square-planar, with the ligands in a trans relationship. 2008 © The Japan Society for Analytical Chemistry.

Determination of Sudan II dye in ethanol fuel by chromatographic and electroanalytical methods

Chromatographic and electroanalytical methods were developed to detect and quantify Sudan II (SD-II) dye in fuel ethanol samples. Sudan II is reduced at +0.50 V vs. Ag/AgCl on a glassy carbon electrode using Britton-Robinson buffer (pH 4.0) and N,N-dimethylformamide (70:30, v/v) + sodium dioctyl sulfosuccinate surfactant as supporting electrolyte, due to the azo group. This is the basis for its determination by square-wave voltammetry (SWV). Using the optimized conditions, it is possible to get a linear calibration curve from 3.00×10-6 to 1.80×10-5 mol L-1 (r = 0.998) with limits of detection (LOD) and quantification (LOQ) of 2.05×10-6 and 6.76×10-6 mol L-1, respectively. In addition, the hydroxyl substituent in the SD-II dye is also oxidized at +0.85 V vs. Ag/AgCl, which was conveniently used for its determination by high-performance liquid chromatography coupled to electrochemical detection (HPLC-ED). Under the optimized condition, the SD-II dye was eluted and separated using a reversed-phase column (cyanopropyl, CN) using isocratic elution with the mobile phase containing acetonitrile and aqueous lithium chloride (5.00×10-4 mol L-1) at 70:30 (v/v) and a flow rate of 1.2 mL min-1. Linear calibration curves were obtained from 3.00×10-7 to 2.00×10-6 mol L-1 (r = 0.999) with LOD and LOQ of 3.10×10-8 and 1.05×10-7 mol L-1, respectively. Both methods were simple, fast and suitable to detect and quantify the dye in fuel ethanol samples at recovery values between 83.0 to 102% (SWV) and 88.0 to 112% (HPLC-ED) with satisfactory precision and accuracy.

Validation of a stability-indicating RP-LC method for the determination of tigecycline in lyophilized powder

A reversed-phase liquid chromatography (RP-LC) method was validated for the determination of tigecycline in lyophilized powder. The LC method was conducted on a Luna C18 column (250 × 4.6 mm i.d.), maintained at room temperature. The mobile phase consisted of buffer containing sodium phosphate monobasic (0.015M) and oxalic acid (0.015M) (pH 7.0)-acetonitrile (75:25, v/v), run at a flow rate of 1.0 mL/min and using ultraviolet detection at 280 nm. The chromatographic separation was obtained with a retention time of 8.6 min, and was linear in the range of 40-100 μg/mL (r2 = 0.9997). The specificity and stability-indicating capability of the method was proven through forced degradation studies, which also showed no interference of the excipients. The accuracy was 99.01% with a bias lower than 1.81%. The limits of detection and quantitation were 1.67 and 5.05 μg/mL, respectively. Moreover, method validation demonstrated satisfactory results for precision and robustness. The proposed method was applied for the analysis of the lyophilized powder formulation, contributing to improve the quality control and to assure the therapeutic efficacy. © The Author [2012]. Published by Oxford University Press. All rights reserved.

Determination of 2-methylimidazole and 4-methylimidazole in caramel colors by capillary electrophoresis

The use of chemical preservative compounds is common in the food products industry. Caramel color is the most usual additive used in beverages, desserts, and breads worldwide. During its fabrication process, 2- and 4-methylimidazole (MeI), highly carcinogenic compounds, are generated. In these cases, the development of reliable analytical methods for the monitoring of undesirable compounds is necessary. The primary procedure for the analysis of 2- and 4-MeI is using LC- or GC-MS techniques. These procedures are time-consuming and require large amounts of organic solvents and several pretreatment steps. This prevents the routine use of this procedure. This paper describes a rapid, efficient, and simple method using capillary electrophoresis (CE) for the separation and determination of 2- and 4-MeI in caramel colors. The analyses were performed using a 75 μm i.d. uncoated fused-silica capillary with an effective length of 40 cm and a running electrolyte consisting of 160 mmol L-1 phosphate plus 30% acetonitrile. The pH was adjusted to 2.5 with triethylamine. The analytes were separated within 6 min at a voltage of 20 kV. Method validation revealed good repeatability of both migration time (<0.8% RSD) and peak area (<2% RSD). Analytical curves for 2- and 4-MeI were linear in the 0.4-40 mg L-1 concentration interval. Detection limits were 0.16 mg L-1 for 4-MeI and 0.22 mg L-1 for 2-MeI. The extraction recoveries were satisfactory. The developed method showed many advantages when compared to the previously used method. © 2013 American Chemical Society.

An HPLC-UV method for the quantification of zidovudine in rat plasma

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação de distribuição de doxorrubicina incorporada em microemulsão lipídica em tecido tumoral e cardíaco em Camundongos

Pós-graduação em Ciências Farmacêuticas - FCFAR

Análise químico-farmacêutica de cefazolina sódica em pó liofilizado para solução injetável

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise químico-farmacêutica de azumoleno sódico

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise químico-farmacêutica de cloridrato de ciprofloxacino em solução oftálmica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise químico-farmacêutica de teicoplanina em pó liofilizado

Pós-graduação em Ciências Farmacêuticas - FCFAR

Farmacocinética pré-clínica e cardiotoxicidade da doxorrubicina veiculada por sistema microemulsionado

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Farmacocinética pré-clínica do composto 1-(2,6-diclorofenil)indolin-2-ona (DICCIC), pró-fármaco de diclofenaco

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise do teor de cocaína em amostras apreendidas pela polícia utilizando-se a técnica de cromatografia liquida de alta eficiência com detector UV-Vis

The HPLC technique with UV-Vis detection was employed in the analysis of cocaine content in apprehended samples of cocaine and crack. A peak signal for cocaine was obtained in 3.5 minutes run by using acetonitrile/water (95:5v/v) as a mobile phase. Optimized spectrophotometric signal was obtained at a wavelength of 224 nm. The analytical curve from 1.0 to 40.0 ppm of cocaine was obtained, showing a linear correlation coefficient of 0.9989, with detection and quantification limits of 0.75 ppm and 3.78 ppm, respectively. This methodology was employed at the dosage of confiscated samples of cocaine and crack in the Scientific Police Laboratory of Ribeirão Preto-SP city.

Determinação de corantes de cabelo e derivados em água e tintura comercial por cromatografia líquida de alta eficiência

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eletroanálise e oxidação fotoeletrocatalítica dos disruptores endócrinos bisfenol A e nonilfenol sobre eletrodo de nanotubos de 'TI'/'TI''O IND.2' auto-organizados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)