Development and validation of analytical method by spectrophotometry UV-Vis for quantification of flavonoids in leaves of Senna occidentalis Link

Senna occidentalis Link (Fabaceae), known as “fedegoso”, is used in folk medicine due to its anti-inflammatory, antioxidant, muscle relaxant and inhibiting lipid peroxidation imputed to flavonoids contained in its composition. The species is also a constituent of processed products are commercialized in various parts of the world including Brazil, although there are few reports in the literature about the development of an analytical method for quantification of flavonoids in it. The main purpose of this research was the evaluation of an analytical methodology to determinate the content of total flavonoids in leaves of S. occidentalis, for quality control. The parameters evaluated were: drug: solvent ratio, concentration of aluminum chloride and reaction time. The quantification of total flavonoids was obtained after reaction with aluminum chloride by UV/Vis spectrophotometry. The results revealed a maximum absorption peak (λ = 392 nm) was the amount of 0.5 g of a plant raw in 100 mL of solvent and there were no significant influences between the concentrations of aluminum chloride or hydroalcoholic solutions analyzed. The evaluation of reaction time allowed to characterize the kinetics as slow, stabilizing from 60 min, choosing this as reading time. The method was specific, linear, precise, accurate and robust, according to the specifications set in RDC n. 166/2017. Finally, the results of the study showed that the measured methodology is simple and accurate and can be applied for quality assessment of the species S. occidentalis.

VALIDATION OF ANALYTICAL METHOD AND INVESTIGATION INTO THE EFFECTS OF BREWING TEMPERATURE ON TOTAL POLYPHENOL CONTENTS IN TEA INFUSIONS PREPARED FROM VIETNAMESE TEA PRODUCTS

Sản xuất từ lá của cây Camellia sinesis L. (Kuntz), trà được xem là một trong những thức uống phổ biến nhất trên thế giới và cây trà được trồng ở khoảng 30 quốc gia. Trong nghiên cứu này, phương pháp Folin-Ciocalteu được áp dụng để xác định hàm lượng polyphenol tổng (quy về milli đương lượng gam của gallic acid, GAE) trong các mẫu trà thành phẩm (ba mẫu trà cổ thụ bao gồm trà đỏ, trà xanh, trà trắng và một mẫu trà oolong) dựa trên ISO 14502-1:2005 với một số thay đổi, cụ thể là chiết một lần bằng dung môi chiết methanol:nước (7:3, v/v) có sự hỗ trợ của siêu âm ở 70 oC với tỉ lệ chiết 0.200:10.00 (g:mL). Phương pháp phân tích được thẩm định trên thiết bị UV-Vis 1800 của hãng Shimadzu với độ tuyến tính phù hợp (R2 > 0.995), khoảng tuyến tính 10-70 mg GAE L–1, độ lặp lại và độ tái lặp tốt (%RSD lần lượt là 0.79 và 1.2% cho độ lặp trong ngày và giữa các ngày) và tỉ lệ phục hồi cao (trên 98% cho các mẫu thêm chuẩn). Hàm lượng polyphenol tổng (giá trị trung bình tính bằng mg GAE g–1 khối lượng khô trong dấu ngoặc đơn) thể hiện xu hướng giảm dần giữa các mẫu trà, cụ thể trà trắng (206.62) trà xanh (201.33) > trà đỏ (167.42) > trà oolong (139.18) do sự khác biệt về mức độ oxy hoá trong quá trình lên men, đặc biệt đối với trà đỏ và oolong. Hàm lượng polyphenol phóng thích vào nước trà thể hiện xu hướng chung tăng dần khi tăng nhiệt độ pha trà, ngoại trừ mẫu trà oolong có xu hướng riêng, có thể do cấu trúc “cuộn xoắn” của loại trà này, dẫn đến thời gian ngâm trà cần phải dài hơn để polyphenol có thể được phóng thích ổn định và hoàn toàn. Nghiên cứu này đóng góp một phần khiêm tốn để làm giàu thêm dữ liệu cho các sản phẩm trà Việt Nam trong bối cảnh lượng trà sản xuất và xuất khẩu cao.

Pesticides Analysis in Beans by Gas Chromatography Couplet with Tandem Mass Spectrometry

Beans are part of the basic diet alimentation for Brazilian population, as they gather proteins, carbohydrates, vitamins, mineral salts, fibers, amino acids and essential nutrients such as iron and calcium, being a complete food that can be compared with the amount of protein that the meat has. Considering the beans world production, in development countries represent almost 50%, being that Myanmar, India and Brazil the top three position. The use of pesticides is widely spread in these countries to reduce agricultural losses due to pests that interfere with grain production. Therefore the risk that could be generated from foods pesticides residues makes their analyses of quantification mandatory. The purpose of this work was to develop an analytical method to quantitatively characterize fungicides pesticides residues, flutriafol, procymidone and tebuconazole that were used to angular spot control, anthracnose, rust and alternaria spot, white mold fungi, present in beans, by means of gas chromatography coupled with a triple quadrupole mass spectrometer. Samples of beans, Phaseolus vulgaris L, types white, black, string and Vigna angularis, type adzuki, had been bought in grains store and supermarkets at metropolitan São Paulo city. The validation of analytical method was explored for sensitivity, selectivity, precision. The extraction procedure was performed in two different forms, QuEChERS, and solid-liquid extraction with low temperature. Through this methodology, reached below the maximum limit allowed by Brazilian law 0.5mgkg-1 for procymidone and 0.1mgkg-1 for flutriafol and tebuconazole. Several samples of four types of beans were tested and all of them had procymidone identified and 7% of samples higher than the law limit.

A NEW INVESTIGATIONAL METHOD FOR QUANTIFICATION AND VALIDATION OF ANALYTICAL METHOD FOR CEFIXIME AND ERDOSTEINE BY UPLC WITH PHOTO DIODE ARRAY DETECTOR IN BULK AND FORMULATION. APPLICATION TO THE ESTIMATION OF PRODUCT TRACES

Specific and innovative method was developed and validated for the identification and quantification of cefixime and erdosteine in the bulk and formulation samples by UPLC with PDA detector.The analytical technique was with buffer (pH: 7.0): methanol, (65:35%, v/v) using the Sunfire C18, 5μ, 46mmX150mm analytical column with analysis time of six minutes. Flow of mobile phase through the column was 1.0 mL/min. Sample volume was 10 μL. Detection was carried at 254 nm in photo diode array detector. The retention times of cefixime and erdosteine were 2.012 min and 3.122 min., respectively. The curve indicates that correlation coefficient (r2) was superior by having the value 1.000 with linear range of 20.0 ng/mL-200.0 ng/mL for Cefixime and 30 ng/mL-300.0 ng/mL for erdosteine. The correlation coefficient (r2) for erdosteine found 1.000. The LoQ for cefixime and erdosteine was 20ng/mL and 30ng/mL respectively. The LOD for cefixime and erdosteine was 1.0 ng/mL and 1.5 ng/mL respectively. The developed method was applied for the bulk and formulation and equipement cleaning sample.