Method development of stir bar sportive extraction coupled with thermal desorption-gas chromatography-mass spectrometry for the analysis of phthalates in Peruvian pisco.

In this work, for the first time, a stir bar sorptive extraction (SBSE) coupled with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was developed and validated for the determination of seven phthalates in Peruvian pisco. The phthalate compounds considered were dimethyl phthalate (DMP), diethyl phthalate (DEP), bis(2-ethylhexyl) hexahydrophthalate (BEHP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di-isodecyl phthalate (DIDP) and di-isobutyl phthalate (DIBP). The best overall analytical conditions obtained from the optimization were as follow: extraction time of 120 min, size of polydimethylsiloxane (PDMS) twister (20 mm length x 1 mm thickness), NaCl content (20 %) and sample volume (40 mL). The in-house validation of SBSE/TD-GC-MS method was performed taking into account the ISO/IEC 17,025 requirements and EURACHEM/CITAC guideline. Under optimal conditions, very low limits of detection of 1.3-0.21 µg L-1 were obtained. Furthermore, the limits of quantification ranged from 4.2-70 µg L-1, and the correlation coefficients were found to be ≥ 0.991. The method was precise, with relative standard deviations (RSD, %) for inter twister repeatability and the inter day repeatability precisions from 1.1 to 11 and from 6.2 to 15.9, respectively. The pisco samples were analysed with recoveries between 91-124.4%, and DBP, BEHP, and BBP were the most commonly found compounds in the samples. The optimized methodology was also evaluated in terms of green character, and it obtained almost the best AGREE score when it was compared with other previous methods for the analysis of phthalates in alcoholic beverages. Therefore, the SBSE/TD-GC-MS method has proved to be suitable for routine practice because it is simple, less laborious, economical, precise, accurate and green, and it would be applicable for pisco safety regulations.

Bacterial cellulose production by Komagataeibacter hansenii can be improved by successive batch culture.

Bacterial cellulose (BC) is a biopolymer principally synthetized by strains of the genus Komagataeibacter. However, high costs and low production yield make large-scale application difficult. The aim of this work was to evaluate the effects of successive batch culture before fermentation on the ability to increase the capacity of bacterial cellulose biosynthesis by a low-producing strain. The Komagataeibacter hansenii strain ATCC 23,769 was initially cultivated in fermentation broth for two periods of 35 or 56 days under static conditions. At the end of each period of time, they were transferred to new broth to be cultivated again (new batch culture cycle) for 35 or 56 days and carried out in parallel with a 10-day fermentation to determine the quantity of BC produced. As a result, a greater increase was observed after the end of the second and third batch cultures of 56 days (increases of 137% and 187% in relation to the nonbatch cultured strain, respectively). The produced samples presented higher crystallinity and thermal properties but lower water holding capacity. Through this work, it was concluded that the longer the batch culture time was, the greater the increase in the capacity of cellulose biosynthesis, which also depended on the number of successive batch culture cycles carried out.

Method development and application to sediments for multi-residue analysis of organic contaminants using gas chromatography-tandem mass spectrometry.

A method for the determination of four classes of potentially toxic substances (PTSs) was developed and applied in marine sediments, including (i) polycyclic aromatic hydrocarbons (PAHs), (ii) polychlorinated biphenyls (PCBs), (iii) polybrominated diphenyl ethers (PBDEs), and (iv) organochlorinated pesticides (OCPs). The method is based on ultrasonic extraction with a mixture of dichloromethane:methanol (9:1 v/v) and gas chromatography coupled with tandem mass spectrometry analysis (GC-MS/MS) in multiple reaction monitoring (MRM) mode. A total of 89 compounds were identified using two precursor-product ion standards for each analyte. The method detection limit (MDL; 0.001-0.055 ng g-1 dw) and method quantification limit (MQL; 0.002-0.184 ng g-1 dw) are below the usual thresholds of pollution adopted by international sediment quality guidelines. The method proved to be selective, sensitive, accurate, and linear, with the advantage of reducing sample handling time and consumable expenses (solvent, adsorbents). The developed method was successfully applied to surface sediments of Sepetiba Bay, Rio de Janeiro State, Brazil. Total concentrations of PAH (29.20-209.5 ng g-1 dw), PCB (0.06-2.16 ng g-1 dw), OCP (0.03-0.33 ng g-1 dw), and PBDE (0.06-0.21 ng g-1 dw) represent a baseline for these compounds and revealed mild to low levels of contamination in comparison to other coastal bays in SE Brazil. By using the proposed method, we expect this preliminary dataset can be expanded and include other similar coastal systems from developing countries marked by scarcity of information about levels, risk assessment, and specific sediment quality guidelines encompassing multiple classes of regulated and emerging organic contaminants.

Development and validation of a HILIC-HPLC-ELSD method for simultaneous determination of glucosamine hydrochloride and chondroitin sulfate in dietary supplements

Abstract The objective of the present study is to develop and validate a simple, selective and accurate hydrophilic interaction liquid chromatography - a high performance liquid chromatography incorporating an evaporative light scattering detector (HILIC-HPLC-ELSD) method for simultaneously determining glucosamine hydrochloride and chondroitin sulfate in dietary supplements. The chromatographic separation was carried out on a ZIC-HILIC column (150 mm x 4.6 mm x 5µm) in isocratic system mode with a mobile phase of acetonitrile, 30 mM ammonium formate and water (77:20:3, v/v/v) at pH 4.5, a column temperature of 35°C, a flow rate of 1 mL.min-1, and an injection volume of 5 µL. An evaporative light scattering (ELS) detector was used. Effective separation was achieved by means of analyte resolution of more than 1.5 with an analysis run time of approximately 20 minutes. The linearity of glucosamine hydrochloride and chondroitin sulfate ranged from 0.4 to 2.5 mg.mL-1. The limits of the detection and quantification of glucosamine hydrochloride were 20 and 80 mg.mL-1 respectively, while for chondroitin sulfate they were 80 and 400 mg.mL-1. All validation parameters satisfied the acceptance criteria in accordance with International Conference on Harmonisation (ICH) guidelines. The method was successfully applied to the assay of commercial dietary supplement samples

Application of capillary zone electrophoresis to determine second-generation H1 antihistaminic drugs, loratadine and rupatadine

Abstract The second generation of H1 antihistamines from the piperidine group are often used for treating allergic diseases due to their action on histaminic receptors, the primary mediator of allergy. Moreover, the antihistamines have anti-inflammatory action, mediated through platelet-activating factor blocking activity. A simple and rapid capillary zone electrophoresis method was developed and validated for the determination of loratadine (LOR) and rupatadine (RUP) in tablets. The analyses were carried out using a fused silica capillary of 50.2 cm (40 cm effective length), 75 µm i.d. The background electrolyte was composed of boric acid 35 mmol/L, pH 2.5. Voltage of 20 kV, hydrodynamic injection of 3447.3 Pa for 3s, temperature at 25 ºC, and UV detection at 205 nm were applied. Electrophoretic separation was achieved at 1.8 and 2.8 min for RUP and LOR, respectively. The method was linear for both drugs in a range of 50.0 to 400.0 µg/mL (r>0.99). The limits of detection and quantification were 46.37 and 140.52 µg/mL, for LOR and 29.60 and 89.69 µg/mL for RUP respectively. The precision was less than 5.0 % for both drugs. The average recovery was approximately 100 %. The proposed novel method can significantly contribute to the rapid detection of counterfeit products and in quality control of drug products containing antihistamines

Toxicological analyses: analytical method validation for prevention or diagnosis.

The need for reliable results in Toxicological Analysis is recognized and required worldwide. The analytical validation ensures that a method will provide trustworthy information about a particular sample when applied in accordance with a predefined protocol, being able to determine a specific analyte at a distinct concentration range for a well-defined purpose. The driving force for developing method validation for bioanalytical projects comes from the regulatory agencies. Thus, the approach of this work is to present theoretical and practical aspects of method validation based on the analysis objective, whether for prevention or diagnosis. Although various legislative bodies accept differing interpretations of requirements for validation, the process for applying validation criteria should be adaptable for each scientific intent or analytical purpose.

Functional analysis of the rat soft palate by real-time wireless electromyography.

OBJECTIVE: The aim of this study was to analyze the function of the palatal muscles in vivo by real-time wireless electromyography in rats. The effects of palatal wounding were also analyzed. METHODS: Microelectrodes were implanted six rats; in the masseter muscle (two-rats) for comparison, in the unwounded soft palate (two-rats) and the soft palate that received a surgical wound (two-rats). Two weeks after implantation, a wound was made in the soft palate using a 1 mm biopsy-punch. Electromyographic measurements and video-recordings were taken weekly to monitor train-duration and peak-amplitude during eating, grooming and drinking. RESULTS: The train-duration of the masseter muscle during eating was 0.49 ±â€¯0.11 s (rat-1) and 0.56 ±â€¯0.09 s (rat-2), which was higher than during grooming. In the unwounded soft palate the train-duration during eating was 0.63 ±â€¯0.12 s (rat-1) and 0.69 ±â€¯0.069 s (rat-2), which was higher than during grooming and drinking. The peak-amplitude for eating in the normal soft palate before surgery was 0.31 ±â€¯0.001 mV (rat-1) and 0.33 ±â€¯0.02 mV (rat-2). This decreased to 0.23 ±â€¯0.03 mV and 0.25 ±â€¯0.11 mV respectively, after surgery. For drinking the peak-amplitude was 0.30 ±â€¯0.01 mV (rat-1) and 0.39 ±â€¯0.01 mV (rat-2) before surgery, which decreased to 0.23 ±â€¯0.09 mV and 0.20 ±â€¯0.14 mV respectively, after surgery. CONCLUSION: The reduced peak-amplitude suggests impaired soft palate function after wounding. This is the first study into the in vivo function of the soft palate after surgical wounding. This model will contribute to develop strategies to improve soft palate function in patients.

A sustainable UPLC-UV method for quantification of donepezil hydrochloride in biorelevant media applied to dissolution profile comparison.

Donepezil hydrochloride is one of the most prescribed anti-Alzheimer's drugs, despite being available for more than two decades, chromatographic methods for the quantification of the drug in biorelevant media that mimics pH physiological conditions in vivo (pH 1.2, 4.5, and 6.8) are not available in the literature. These media are used in the dissolution test, an important tool, for registration and quality control of medicines. Considering the need for methods with this purpose, this work aimed to develop and validate a sustainable UPLC-UV method for quantification of donepezil hydrochloride in tablets, specifically on assay and dissolution profile, with reduced environmental impacts. The proposed method has a run time of 2 min and requires for each run, only 0.8 mL of solvents, providing excellent green analysis. The method proved to be selective, linear, precise, accurate, robust in the range of 2-14 µg/mL. Three products (reference, similar, and generic) were analyzed and showed very rapid dissolution. The average content varied from 100.2 ± 0.6% to 109.5 ± 2.1%. Using dissolution efficiency (DE), the drug release profiles were compared in different biorelevant media.

Polychlorinated biphenyls (PCBs) in water: method development and application to river samples from a populated tropical urban area.

A method for the determination of polychlorinated biphenyls (PCBs) in water from urban rivers was implemented and validated. Extractions of dissolved and particulate PCBs were performed using solid-phase extraction and a pressurized solvent extraction system, respectively, and the analytes were identified and quantified by gas chromatography with tandem mass spectrometry in selected reaction monitoring mode with no further purification. The method was successfully developed for the determination of 41 PCBs with two precursor-product confirmations for each analyte. Low method detection limits (0.06-0.50 ng L-1) and good precision (≤ 20%; n = 8) were obtained, as well a linear response of the calibration curve ranging from 1.0 to 50 ng L-1. Method performance for real samples was tested with water collected weekly in triplicate during April 2018 from a eutrophic river in the city of Rio de Janeiro. The total (dissolved + particulate) PCB concentrations ranged from 2.17 to 5.29 ng L-1, above the threshold for river water quality standards in Brazil. Graphical abstract.

Development and validation of a stability indicating high performance liquid chromatography method for trimethobenzamide

A simple, accurate, precise and robust stability indicating RP-HPLC assay method has been developed for the estimation of trimethobenzamide in stress sample. An isocratic separation of trimethobenzamide was achieved on Kromasil 100 C-18 column (250 X 4.6mm, 5µ) with a flow rate of 1.0 ml/min and by using a photodiode array detector to detect the analyte at 213nm. The optimized mobile phase consisted of methanol: ammonium formate (44:56, v/v). The drug was subjected to different forced degradation conditions according to ICH guidelines including acid, base, neutral hydrolysis, oxidation, photolysis and thermal degradation. Degradation products were found only in basic and oxidative degradation conditions. All the degradation products got eluted in an overall analytical run time of 12min. The developed analytical method has been validated according to the ICH guidelines. Response of trimethobenzamide was linear over the concentration range of 0.5-50µg/mL (r2 = 0.999). Accuracy was found to be in between 94.03% to 100.39%. Degradation products resulting from the stress studies did not interfere with the detection of the analyte.

Experimental Design Methodologies for the Optimization of Chiral Separations: An Overview.

In this chapter, the application of design of experiments (DoE) for chiral separation optimization using supercritical fluid chromatography (SFC), liquid chromatography (LC), capillary electrophoresis (CE), and capillary electrochromatography (CEC) methods is reviewed. Both screening and optimization steps are covered, including a discussion of each aspect, such as factor-, level-, and response selection. Different designs are also presented, highlighting their applications.

Validation of a liquid chromatography/tandem mass spectrometry method for the detection of aflatoxin B1 residues in broiler liver / Validación de una técnica para detectar aflatoxina B1 en hígado de pollo por cromatografía líquida de alta performance acoplada a espectrómetro de masas en tándem

Aflatoxin B1 is a carcinogenic and mutagenic mycotoxin produced mainly by Aspergillus flavus and Aspergillus parasiticus. It is the predominant mycotoxin found in raw materials used for the manufacture of broiler feeds. The aim of the present study was to develop a new and optimized method for the detection and quantification of aflatoxin B1 (AFB1) residues in broiler liver using solid phase extraction (SPE) clean-up and liquid chromatography-electrospray ionization/tandem mass spectrometry (LC-ESI-MS/MS) detection. The method was validated for linearity, accuracy, precision, limit of detection (LOD) and limit of quantification (LOQ). The validation parameters indicated satisfactory linearity (r² >0.99), accuracy and precision (4.57% intra-day RSD; 14.65% inter-day RSD) a very high recovery (99 ±13%) and high sensitivity achieved for AFB1 in animal samples (LOD = 0.017 and LOQ= 0.050 ng/g). The method was effective for the detection and quantification of AFB1 residues in broiler liver and could also be potentially used for detecting AFB1 in other edible animal tissues after natural or experimental AFB1 exposure with high sensitivity and precision.

La aflatoxina B1 (AFB1) es una micotoxina carcinogénica y mutagénica producida principalmente por Aspergillus flavus y Aspergillus parasiticus. Es la principal toxina que contamina las materias primas utilizadas para la elaboración de alimentos balanceados destinados a la alimentación de pollos parrilleros. El objetivo de este trabajo fue desarrollar un método nuevo y optimizado para detectar y cuantificar bajos niveles de AFB1 en hígado de pollo, usando limpieza por extracción en fase sólida (SPE) y cromatografía líquida acoplada a detección por espectrometría de masa en tándem con ionización por electrospray (LC-ESI-MS/MS). Se validaron la linealidad, la exactitud, la precisión, el límite de detección (LOD) y el límite de cuantificación (LOQ). El método resultó tener linealidad (r²>0,99), exactitud y precisión muy satisfactorias (4,57% RSD intradía; 14,65% RSD interdía), un alto porcentaje de recupero (99 ± 13%) y la sensibilidad más alta lograda para la detección de AFB1 en muestras de origen animal (LOQ=0.050 ng/g y LOD = 0.017). El método fue muy efectivo para detectar y cuantificar bajos niveles de AFB1 en hígados de pollos parrilleros. Este método podría potencialmente utilizarse para la detección de esta toxina en otros tejidos y subproductos de origen animal luego de su exposición a AFB1 con una mayor sensibilidad y precisión.

Validation of a liquid chromatography/tandem mass spectrometry method for the detection of aflatoxin B1 residues in broiler liver.

Aflatoxin B1 is a carcinogenic and mutagenic mycotoxin produced mainly by Aspergillus flavus and Aspergillus parasiticus. It is the predominant mycotoxin found in raw materials used for the manufacture of broiler feeds. The aim of the present study was to develop a new and optimized method for the detection and quantification of aflatoxin B1 (AFB1) residues in broiler liver using solid phase extraction (SPE) clean-up and liquid chromatography-electrospray ionization/tandem mass spectrometry (LC-ESI-MS/MS) detection. The method was validated for linearity, accuracy, precision, limit of detection (LOD) and limit of quantification (LOQ). The validation parameters indicated satisfactory linearity (r2>0.99), accuracy and precision (4.57% intra-day RSD; 14.65% inter-day RSD) a very high recovery (99±13%) and high sensitivity achieved for AFB1 in animal samples (LOD=0.017 and LOQ=0.050ng/g). The method was effective for the detection and quantification of AFB1 residues in broiler liver and could also be potentially used for detecting AFB1 in other edible animal tissues after natural or experimental AFB1 exposure with high sensitivity and precision.

Stability indicating RP-HPLC method development and validation of cefepime and amikacin in pure and pharmaceutical dosage forms

A simple, accurate, isocratic stability indicating RP-HPLC method was developed for the determination of cefepime and amikacin in Pure and its pharmaceutical formulations. The method consists of methanol: acetonitrile:acetate buffer 75:20:05 (v/v) mobile phase at pH 5.1 with C18 column as stationary phase. The flow rate and detection wave length were 1.0 mL/min and 212 nm respectively. The linearity range for the method was found to be 2.5-25 µg/mL for amikacin and 10-100 µg/mL cefepime respectively. The developed method was validated as per ICH guidelines and the results of all the validation parameters were well within their acceptance values. Also the forced degradation studies were conducted with standard drugs. Degradation products formed during the different stress conditions were separated from both drugs. This validated method was applied for the simultaneous estimation of cefepime and amikacin in commercially available formulation sample.

Higher detectability method for the analysis of nucleosides, putative tumor biomarkers, in blood serum samples by CE-UV with reversed EOF.

The development and validation of methodologies for the analysis of biological samples is of outcome importance in order to obtain trustworthy results. This work reports a novel CE-UV method for the assessment of nucleosides, putative tumor biomarkers, in blood serum. The separation of seven nucleosides within c.a. 20 min has been achieved with: BGE 30 mmol/L borate at pH 9.90, 50 mmol/L CTAB, and 10% methanol; V = -10 kV; T = 20°C; and capillary dimensions of 56 cm × 50 µm. The sample plug was concentrated by a modified large volume sample stacking strategy that provided better detectability. Validation showed that the method is suitable for bioanalytical purposes and initial applications in serum samples from healthy subjects are also presented. Finally, statistical methods were applied to verify the effect of characteristics such as age, smoking habits, and alcohol consumption on nucleoside concentrations in blood serum. Univariate statistical analysis tests emphasized the need for age matching, which was confirmed by PCA-DA and PLS-DA. Cancer history in the nearby family may also interfere in nucleoside levels in blood serum, since adenosine concentrations were statistically higher for volunteers who declared having diseased relatives.

Fast method for capsaicinoids analysis from Capsicum chinense fruits.

Chili peppers are widely utilized in the world as savory food additives due the pungency induced by the capsaicinoids. Also, these compounds have functional properties as antimutagenic, antitumoral, antioxidant and analgesic. These characteristics increase the interest in this compound class, hence the capsaicinoid analysis must be reproducible and accurate. This study aimed to develop and validate a fast, efficient and reproducible method to analyze capsaicinoids in Brazilian Capsicum chinense fruits. The extracts were obtained after an optimization step that indicated the condition 100% of methanol and 10min on ultrasound assisted extraction. The analyses were carried out in an ultra high performance liquid chromatographic system with detection by a photo diode array and mass spectrometer. The analytical method developed permits the separation of 8 capsaicinoids in 4min of time analysis expending only 2mL of solvent as mobile phase. The validation parameters evaluated for the method show the effectiveness and satisfactory performance to answer the analytical needs of this research area, presenting low values to relative standard deviation in repeatability and reproducibility and recoveries ranged from 88 to 112% for capsaicin and 89 to 109% for dihydrocapsaicin. In the extracts from different accessions of C. chinense fruits analyzed, the contents of capsaicin and dihydrocapsaicin were in the range of 156-1442µgg-1 and 26-478µgg-1 of fresh fruit, respectively, showing the large application of this method for quantification of the two major capsaicinoids in fast routine analysis and may be used to determine the concentrations of other minor capsaicinoids once appropriate standards are available.

Development and validation of a dissolution method using HPLC for diclofenac potassium in oral suspension

The present study describes the development and validation of an in vitro dissolution method for evaluation to release diclofenac potassium in oral suspension. The dissolution test was developed and validated according to international guidelines. Parameters like linearity, specificity, precision and accuracy were evaluated, as well as the influence of rotation speed and surfactant concentration on the medium. After selecting the best conditions, the method was validated using apparatus 2 (paddle), 50-rpm rotation speed, 900 mL of water with 0.3% sodium lauryl sulfate (SLS) as dissolution medium at 37.0 ± 0.5°C. Samples were analyzed using the HPLC-UV (PDA) method. The results obtained were satisfactory for the parameters evaluated. The method developed may be useful in routine quality control for pharmaceutical industries that produce oral suspensions containing diclofenac potassium.

O presente estudo descreve o desenvolvimento e validação de um método de dissolução in vitro para avaliação da liberação de diclofenaco potássico suspensão oral. O teste de dissolução foi desenvolvido e validado de acordo com as diretrizes internacionais. Parâmetros como linearidade, especificidade, precisão e exatidão foram avaliados, bem como a influência da velocidade de rotação e a concentração de tensoativono meio. Depois de selecionar as melhores condições, o método foi validado usando o aparato 2 (pás), velocidade de rotação de 50 rpm, 900 mL de água com 0,3% de lauril sulfato de sódio (LSS) como meio de dissolução a 37,0 ± 0,5 ºC. As amostras foram analisadas pelo método de CLAE-UV (PDA). Os resultados obtidos foram satisfatórios para os parâmetros avaliados. O método desenvolvido pode ser útil na rotina de controle de qualidade para as indústrias farmacêuticas que produzem suspensões orais contendo diclofenaco potássico.

HPLC method development for the simultaneous analysis of amlodipine and valsartan in combined dosage forms and in vitro dissolution studies

A simple, rapid and reproducible HPLC method was developed for the simultaneous determination of amlodipine and valsartan in their combined dosage forms, and for drug dissolution studies. A C18 column (ODS 2, 10 μm, 200 x 4.6 mm) and a mobile phase of phosphate buffer (pH 3.6 , 0.01 mol L-1):acetonitrile: methanol (46:44:10 v/v/v) mixture were used for separation and quantification. Analyses were run at a flow-rate of 1 mL min-1 and at ambient temperature. The injection volume was 20 μL and the ultraviolet detector was set at 240 nm. Under these conditions, amlodipine and valsartan were eluted at 7.1 min and 3.4 min, respectively. Total run time was shorter than 9 min. The developed method was validated according to the literature and found to be linear within the range 0.1 - 50 μg mL-1 for amlodipine, and 0.05 - 50 μg mL-1 for valsartan. The developed method was applied successfully for quality control assay of amlodipine and valsartan in their combination drug product and in vitro dissolution studies.

Desenvolveu-se método de HPLC rápido e reprodutível para a determinação simultânea de anlodipino e valsartana em suas formas de associação e para os estudos de dissolução dos fármacos. Utilizaram-se coluna C18 (ODS 2, 10 μm, 200 x 4,6 mm) e fase móvel tampão fosfato (pH 3,6, 0,01 mol L-1):acetonitrila: metanol para a separação e a quantificação. As análises foram efetuadas com velocidade de fluxo de 1 mL min-1 e à temparatura ambiente O volume de injeção foi de 20 μL e utilizou-se detector de ultravioleta a 240 nm. Sob essas condições, anlodipino e valsartana foram eluídas a 7,1 min e 3,4 min, respectivamente. O tempo total de corrida foi menor que 9 min. O método desenvolvido foi validado de acordo com a literatura e se mostrou linear na faixa de 0,1-50 μg mL-1 para anlodipino e de 0,05-50 μg mL-1 para valsartana. O método desenvolvido foi aplicado com sucesso para ensaios de controle de qualidade de associações de anlodipino e valsartana e nos estudos de dissolução in vitro.

Development and validation of an HPLC method for the determination of epicatechin in Maytenus ilicifolia (Schrad.) Planch., Celastraceae / Desenvolvimento e validação de um método de CLAE para a determinação da epicatequina em Maytenus ilicifolia (Schrad.) Planch., Celastraceae

A simple, reproducible and efficient high-performance liquid chromatography (HPLC) method was developed. Water (0.05 percent TFA):acetonitrile (0.05 percent TFA) was used as the mobile phase in a gradient system for the determination of epicatechin (EP) in leaves of Maytenus ilicifolia (Schrad.) Planch. The analysis was performed using an RP C-18 column (5 µm) as the stationary phase, with a flow rate of 0.8 mL/min, at a wavelength of 210 nm for detection and determination. The main validation parameters of the method were also determined. The calibration curve was found to be linear, with a range of 10-120 µg/mL (EP). The correlation coefficient of the linear regression analysis was within 0.9988, and the detection and quantification limits were 28.61 and 86.77 µg/mL, respectively. The content of EP was successfully determined, with satisfactory reproducibility and recovery. Recovery of the EP was 99.32 percent. The method was successfully applied to the determination of epicatechin in leaves of M. ilicifolia. The interlaboratorial evaluation showed the reproducibility of the method with a relative standard deviation of 14.62 percent.

Um método simples, reprodutível e eficiente de cromatografia líquida de alta eficiência (CLAE) foi desenvolvido. Água (0,05 por cento TFA):acetonitrila (0,05 por cento TFA) foi utilizado como fase móvel em um sistema de gradiente para a determinação da epicatequina (EP) em folhas de Maytenus ilicifolia (Schrad.) Planch., Celastraceae. A análise foi realizada utilizando coluna RP C-18 (5 µm) como fase estacionária, com vazão de 0,8 mL/min, e comprimento de onda de 210 nm para a detecção e determinação. Os principais parâmetros de validação do método foram determinados. A curva analítica apresentou-se linear no intervalo de 10-120 µg/mL (EP). O coeficiente de correlação da análise de regressão linear foi de 0,9988, o limite de detecção e o limite de quantificação foram de 28,61 e 86,77 µg/mL, respectivamente. O conteúdo do EP foi determinado com sucesso, com boa reprodutibilidade e recuperação. Recuperação da EP foi 99,32 por cento. O método foi aplicado com sucesso na determinação da epicatequina em folhas de M. ilicifolia. A avaliação interlaboratorial demonstrou a reprodutibilidade do método com desvio padrão relativo de 14,62 por cento.