Determinação de 2,5-hexanodiona em urina empregando cromatografia líquida de alta eficiência, após derivatização com 2,4-dinitrofenil-hidrazina

A method for quantifying urinary 2,5-hexanedione was optimized and validated. Urine samples were hydrolyzed and derivatized with 2,4-dinitrophenylhydrazine. The analyte was separated in a high performance liquid chromatography system with a diode array detector, using a C18 column (150 x 4.6 mm, p.d. 5 µm) and a mobile phase composed of phosphate buffer pH 2.3:acetonitrile (40:60, v/v), at a flow rate of 1 mL/min. The chromatograms were monitored at 334 nm. Retention time was 7.3 minutes. Main validation parameters were: coefficient of determination: 0.9994, accuracy: 96 to 107%; intra-assay precision (RSD): 3.08 to 6.72%; inter-assay precision (RSD): 2.54 to 8.17% and limit of quantitation of 0.19 µg/mL.

Development and validation of a stability-indicating UPLC method for rosuvastatin and its related impurities in pharmaceutical dosage forms

The present work describes a novel stability-indicating reversed-phase ultra performance liquid chromatography method for the separation and quantification of rosuvastatin (RSV) and its related impurities in the pharmaceutical dosage forms under forced degradation conditions. An unknown degradation impurity detected in the acid degradation was identified by using quadrupole time-of-flight mass spectrometry. The chromatographic separation was carried out on C-18 column (100 x 2.1 mm, 1.7 μm) using isocratic elution with methanol and 0.1% trifluoroacetic acid (50:50). The total run time was 12 min within which RSV as well as all related impurities and degradation products were separated. The developed method was validated for RSV and related impurities in pharmaceutical dosage forms.

Development and validation of a dissolution test for diltiazem hydrochloride in immediate release capsules

This work describes the development and validation of a dissolution test for 60 mg of diltiazem hydrochloride in immediate release capsules. The best dissolution in vitro profile was achieved using potassium phosphate buffer at pH 6.8 as the dissolution medium and paddle as the apparatus at 50 rpm. The drug concentrations in the dissolution media were determined by UV spectrophotometry and HPLC and a statistical analysis revealed that there were significant differences between HPLC and spectrophotometry. This study illustrates the importance of an official method for the dissolution test, since there is no official monograph for diltiazem hydrochloride in capsules.

Aplicações de cromatografia líquida de alta eficiência para o estudo de poluentes orgânicos emergentes

Emerging organic pollutants (EOP) include many environmental contaminants based on commercial products such as pharmaceuticals, personal care products, detergents, gasoline, polymers, etc. EOP may be candidates for future regulation as they offer potential risk to environmental and human health due to their continual entrance into the environment and to the fact that even the most modern wastewater treatment plants are not able to totally transform / remove these compounds. High performance liquid chromatography is recommended to separate emerging organic pollutants with characteristics of high polarity and low volatility, especially pharmaceuticals, from environmental matrices.

Otimização e validação de método empregando quechers modificado e lc-esi-ms/ms para determinação de agrotóxicos em cebola

An evaluation of the pesticides extraction from onion using a modern sample preparation method (QuEChERS) and determination by liquid chromatography tandem mass spectrometry was carried out. All the calibration curves showed r>0.99. The recoveries ranged between 61.8 and 120.0% with relative standard deviation lower than 20% for all compounds. Due to the occurrence of matrix effect, the quantification was performed using matrix-matched calibration. The limits of quantification of the method were between 0.0005 and 0.05 mg kg-1. The method shows the advantages of not require the clean-up step and consume low volume of organic solvents, decreasing time, costs and residues.

Cromatografia líquida capilar: estado da arte e aplicações

This review describes the advantages and disadvantages of using capillary liquid chromatography (CLC), which is considered the newest member in the analytical separation science arsenal. Although CLC has tremendous potential for being the next major innovation in separatory analysis, it has not yet obtained great popularity compared to conventional high performance (and ultra-high performance) liquid chromatography. Comparisons are made between these techniques and some of the reasons that CLC has not yet reached its potential will be advanced.

Identificação de alguns constituintes químicos de Indigofera hirsuta Linn. (Fabaceae) por CLAE-IES-EM (TOF) e avaliação da atividade antirradicalar

A rapid analytical approach, suitable to characterize the compounds present in the aqueous and methanol extracts prepared from the aerial parts of Indigofera hirsute, was developed. The method based on high-performance liquid chromatography coupled to mass spectrometry, electrospray positive ionization and detection by time of flight (HPLC-ESI-MS-TOF) identified, tryptophan, uracil, rutin, kaempferol-3-O-β-D-glucopyranoside, gallic acid and methyl gallate. The antiradical activity of this extract was evaluated using DPPH assay, with gallic acid as antiradical pattern. The study revealed the antiradical activity of methyl galatte (EC50 = 5 ± 0.3 µg mL-1) galic acid (EC50 = 5 ± 0.2 µg mL-1) and rutin (EC50 = 21.6 ± 0.6 µg m L-1), isolated from methanol extract (EC50 = 67.7 ± 0.9 µg mL-1), which showed strong antiradical activity.

Determinação rápida de oseltamivir em cápsulas por cromatografia líquida de ultraeficiência com detector por arranjo de diodos

A simple and rapid ultra-performance liquid chromatographic method for determination of oseltamivir in capsules was developed and validated. The mobile phase consisted of 5 mmol/L triethylammonium buffer (pH 3.0) and acetonitrile (70:30, v/v). Separation was performed in a Hypersil Gold® column, with octylsilil as stationary phase (100 x 2.1 mm, p.d. 1.9 µm). Chromatography run time was 1.2 min. The method presented adequate specificity, linearity, precision, ruggedness and accuracy and was adequate for determination of oseltamivir in capsules.

Principais técnicas de preparo de amostra para a determinação de resíduos de agrotóxicos em água por cromatografia líquida com detecção por arranjo de diodos e por espectrometria de massas

The determination of pesticide residues in water samples by Liquid Chromatography require sample preparation for extraction and enrichment of the analytes with the minimization of interferences to achieve adequate detection limits. The Solid Phase Extraction (SPE), Solid Phase Microextraction (SPME), Stir Bar Sorptive Extraction (SBSE) and Dispersive Liquid-Liquid Microextraction (DLLME) techniques have been widely used for extraction of pesticides in water. In this review, the principles of these sample preparation techniques associated with the analysis by Liquid Chromatography with Diode Array Detection (LC-DAD) or Mass Spectrometry (LC-MS) are described and an overview of several applications were presented and discussed.

Validação de método e determinação espectrométrica dos flavonoides das folhas e do vinhoto da cana-de-açúcar e comparação com método CLAE-UV

This paper reports on a modification of the procedures originally described in the French Pharmacopoeia for the UV-visible spectrometric analysis of flavonoids, and proposes a validation of the method and its application in the determination of total flavonoids from sugarcane (Saccharum officinarum) leaves and vinasse. An analysis of precision and accuracy revealed a low relative standard deviation (< 5.0%) and a good recovery percentages (99.79 and 98.34%). A comparison of the spectrometric results against those obtained by high performance liquid chromatography (HPLC-UV) demonstrated complete compatibility between the modified French Pharmacopoeia (spectrometric) and HPLC-UV methods

Validação de método multirresíduo para determinação de pesticidas em alimentos empregando QuEChERS E UPLC-MS/MS

This paper presents a practical and rapid method which was validated for simultaneous quantification and confirmation of 29 pesticides in fruits and vegetables using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted following the method known as QuEChERS. Using the developed chromatographic conditions, the pesticides can be separated in less than 9 min. Two multiple reaction monitoring (MRM) assays were used for each pesticide. Four representative matrices (lettuce, tomato, apple and grapes) were selected to investigate the effect in recoveries and precision. Typical recoveries ranged from 70-120%, with relative standard deviation (RSDs) lower than 20%.

Gemifloxacin mesylate: UV spectrophotometric method for quantitative determination using experimental design for robustness

This study describes the validation of UV spectrophotometric method for quantitative determination of gemifloxacin mesylate (GFM) in tablets using methanol as solvent. The method was specific, linear, precise, exact and robust at 272 and 343 nm. The results confirmed that the method in both wavelengths is valid and useful to the routine quality control of GFM in coated tablets. The validate method was compared to liquid chromatography (HPLC), microbiological assay and visible (VIS) spectrophotometry, which were previously developed and validated to the same drug. There was not significative difference between the methods for GFM quantitation.

Development and validation of a stability-indicating HPLC method for the determination of buclizine hydrochloride in tablets and oral suspension and its application to dissolution studies

A method using liquid chromatography has been developed and validated for determination of buclizine in pharmaceutical formulations and in release studies. Isocratic chromatography was performed on a C18 column with methanol:water (80:20 v/v, pH 2.6) as mobile phase, at a flow rate of 1.0 mL/min, and UV detection at 230 nm. The method was linear, accurate, precise, sensible and robust. The dissolution test was optimized and validated in terms of dissolution medium, apparatus agitation and rotation speed. The presented analytical and dissolution procedures can be conveniently adopted in the quality and stability control of buclizine in tablets and oral suspension.

A validated method using RP-HPLC for quantification of reserpine in the Brazilian tree Rauvolfia sellowii Müll. Arg. (Apocynaceae)

This study describes a simple, fast and reproducible method using RP-HPLC-UV, in a gradient system, for quantification of reserpine in Rauvolfia sellowii stem bark. The analysis were carried out on a C18 column; mobile phase was water and acetonitrile, and separations were carried out in 10 min, flow rate of 1.0 mL min-1, 25 ºC and 268 nm. The validation data showed that the method was specific, accurate, precise and robust. Results were linear over a range of 0.625-40.0 μg mL-1, and the mean recovery was 95.1%. The amount of reserpine found in the dried stem bark was 0.01% (m/m).

Desenvolvimento e validação de método analítico por CLAE para a quantificação simultânea de dipropionato de betametasona e fosfato sódico de betametasona em suspensão injetável

A reversed-phase HPLC method was developed and validated to separate and simultaneously quantify the association of betamethasone sodium phosphate (BP) and betamethasone dipropionate (BD) in injectable suspensions. Chromatographic conditions were ternary gradient elution at 1.6 mL/min on a C18 column with 254 nm. The linearity of the method was established in the range 120 to 280 mg/mL BD, and 48 to 112 mg/mL BP. The RSD of intermediate precision of the method was <1% and recoveries were 99-101% for both drugs. The method proved selective, linear, precise, accurate and robust for quantifying BP and BD in commercial injectable suspensions.