Assessment of Pesticide Residues in Some Fruits Using Gas Chromatography Coupled with Micro Electron Capture Detector

A very sensitive analytical method for the determination of 26 pesticides in some fruits based on solid phase extraction (SPE) cleanup was developed using gas chromatography (GC) coupled with micro electron capture detector (μECD). The identity of the pesticides was confirmed by gas chromatography mass spectroscopy (GC-MS) using selected ion monitoring (SIM) mode. Ethyl acetate was used as a solvent for the extraction of pesticide residues with assistance of sonication. For cleanup an octadecyl, C18 SPE column was used. A linear response of μECD was observed for all pesticides with good correlation coefficients (>0.9992). Proposed method was successfully applied for the determination of pesticide residues in the orange, apple, and grape fruits. Average recoveries achieved for all of the pesticides at fortification levels of 0.05, 1.0 and 2.0 μg g-1 in analyzed fruits were above 90% with relative standard deviations (RSD) less than

Perspectivas del perfil de ácidos grasos y la composición de lípidos bioactivos de semillas en la discriminación de variedades de manzana mediante quimiometría

The extracted oils from four apple seed varieties (Royal Gala, Red Delicious, Pyrus Malus and Golden Delicious) from Pakistan were investigated for their fatty acid profiles and lipid biactives by GC-MS. The oil contents in the seeds of the apple varieties ranged from 26.8-28.7%. The results revealed that linoleic acid (40.5-49.6%) was the main fatty acid in the Royal Gala, Red Delicious and Pyrus Malus seeds, and oleic acid (38.7-45.5%) was the main fatty acid in the Golden Delicious seeds. Palmitic acid (6.1-7.4%) and stearic acid (2.0-3.1%) were the dominant saturated fatty acids, besides the small amount of palmitoleic, heptadecanoic, linolenic, archidic, eicosanoic, and behenicacids. Sterols, tocopherols, hydrocarbons and some other minor components were also identified from the unsaponifiable lipid fraction. The variation among the results of both fatty acids and lipid bioactives for the four different varieties was assessed by principal component analysis, discriminant analysis and cluster analyses. The results conclude that both oil fractions could be applied as a useful tool to discriminate among the apple seed varieties.Se ha estudiado el perfil de ácidos grasos y lípidos biactivos mediante GC-MS del aceite extraído de semillas de cuatro variedades de manzanas de Pakistán (Royal Gala, Red Delicious, Pyrus Malus y Golden Delicious). El contenido de aceite en las semillas de las variedades de manzanas estudiadas oscilaron desde 26,8 hasta 28,7%. Los resultados mostraron que el ácido linoleico (40.5-49.6%) fue el principal ácido graso de las semillas de las variedades Royal Gala, Red Delicious y Pyrus Malus, y el ácido oleico (38,7-45,5%) fue el principal ácido graso de Golden Delicious. Los ácidos palmítico (6.1-7.4%) y esteárico (2,0-3,1%) fueron los ácidos grasos saturados predominantes, las semillas contenían también pequeñas cantidades de palmitoleico, heptadecanoico, linolénico, araquídico, eicosanoico, y behénico. Esteroles, tocoferoles, hidrocarburos, y otros componentes menores también fueron identificados a partir de la fracción insaponificable. La variación de los resultados de ambos, ácidos grasos y lípidos bioactivos, de cuatro variedades diferentes se evaluó mediante análisis de componentes principales, análisis discriminante y análisis de cluster. Los resultados concluyen que las dos fracciones lipídicas de semillas de manzanas podrían aplicarse como una herramienta útil para distinguir variedades

Determinación rápida de trazas metálicas en aceites y grasas

An atomic absorption spectrophotometric method has been devised for the rapid determination of trace metals, found in several vegetable oils and fats. Samples were prepared using an ultrasonically assisted acid-extractive technique. The parameters of the analysis were optimized to improve the recovery of metals from the oil matrixes at an ultra trace level within the least possible time. The use of ultrasonic intensification, followed by centrifugation for phase separation reduced the conventional acid extraction time from 180 to only 10 minutes. The respective range of recovery of iron, copper, nickel and zinc was found to be 94.6-98.0 %, 93.6-100.4 %, 95.0-97.3 % and 96.0-101.2 % in a soybean oil which was fortified with 0.10, 0.25, 0.50, 0.75, 1.00 μg/gm of each of the metals using the standard addition method. The ranges of recovery of these metals as investigated by the proposed method were also found in close agreement with those of the wet digestion method. Most of the samples of commercial oils and fats were found to be contaminated with notable amounts of iron and nickel ranging from 0.13-2.48 and 0.027-2.38 ppm respectively. The contents of copper and zinc were also high in many brands, ranging from 0.01-0.15 ppm and zinc 0.03- 0.21 ppm respectively, which poses a threat to oil quality and to human health.Se ha establecido un método analítico rápido mediante espectroscopia de absorción atómica para determinar con rapidez trazas metálicos en algunos aceites y grasas. Las muestras se preparan mediante una técnica extractiva que utiliza ultrasonidos. Los parámetros del análisis han sido optimizados para mejorar la recuperación de metales a niveles de ultra-traza en el menor tiempo posible. El uso de ultrasonidos, seguido por centrifugación para la separación de fases, redujo el tiempo convencional de extracción de 180 a 10 min. Los rangos de recuperación de hierro, cobre, níquel y zinc fueron 94.6-98.0 %, 93.6-100.4 %, 95.0-97.3 % y 96.0-101.2 %, respectivamente, cuando se utilizó un aceite de soja fortificado con 0.10, 0.25, 0.50, 0.75, 1.00 μg/gm de cada metal utilizando el método estándar de adición. Los rangos de recuperación de los metales fueron muy similares a los obtenidos mediante el método de digestión húmeda. En la mayor parte de las muestras de aceites y grasas analizadas se encontraron cantidades significativas de hierro y níquel que oscilaron entre 0.13-2.48 ppm y 0.027-2.38 ppm, respectivamente, mientras que los contenidos de cobre y zinc oscilaron entre 0.01-0.15 ppm y 0.03- 0.21 ppm, respectivamente

Cathodic Stripping Voltammetric Determination of Cefadroxil in Pharmaceutical Preparations and in Blood Serum

Abstract An analytical method has been developed using hanging mercury drop electrode (HMDE) for the quantitative determination of antibacterial drug cefadroxil (CFL) from pharmaceutical preparations and blood serum. Cathodic adsorptive stripping voltammetry was carried out in hydrochloric acid (0.1M): methanol (80: 20 v/v) and potassium chloride (0.1M) as supporting electrolyte. The reduction wave was obtained within -700 to -800 mV. Linear calibration curve was within 1-50µg/mL with detection limit of 0.1µg/mL of cefadroxil. Relative standard deviation for inter and intra day analysis of CFL was within 1-2%. The number of additives present in pharmaceutical preparations did not interfere the determination of cefadroxil. The analysis of pharmaceutical preparations and blood serum after chemotherapy with cefadroxil indicated relative standard deviation (RSD) within 0.8-1.2% and 2.6-3.8% respectively. The satisfactory results were obtained for quality control of cefadroxil in pharmaceutical preparations and in blood serum

Multi-component quantitation of loratadine, pseudoephedrine and paracetamol in plasma and pharmaceutical formulations with liquid chromatography-tandem mass spectrometry utilizing a monolithic column

The purpose of this study was to develop a rapid, simple and sensitive quantitation method for pseudoephedrine (PSE), paracetamol (PAR) and loratadine (LOR) in plasma and pharmaceuticals using liquid chromatography-tandem mass spectrometry with a monolithic column. Separation was achieved using a gradient composition of methanol-0.1% formic acid at a flow rate of 1.0 mL min-1. Mass spectral transitions were recorded in SRM mode. System validation was evaluated for precision, specificity and linearity. Limit of detection for pseudoephedrine, paracetamol, and loratadine were determined to be 3.14, 1.86 and 1.44 ng mL-1, respectively, allowing easy determination in plasma with % recovery of 93.12 to 101.56%

Micellar liquid chromatographic determination of aluminum as its complex with 8-hydroxyquinoline-5-sulfonic acid

SUMMARY A micellar liquid-chromatographic method is proposed for determination of Al(III) as the 8-hydroxyquinoline-5-sulfonic acid derivative, with spectrofluorimetric detection. Cetyltrimethylammonium bromide, a cationic surfactant (0.05 M), was used as mobile phase. The metal chelate was detected at λ Ex 410 and λ Em 510 nm. Response to aluminum is selective in the presence of other metal ions. The method eliminates the need for addition of reagent or organic modifier to the mobile phase, as is normal in RP HPLC. Under optimized conditions the linear range was 20-200 µg L −1 Al(III), the limit of detection 10 µg L −1 , and the limit of quantification 40 µg L −1 . The method was used to determine aluminum in a variety of water samples

Comparison of Fatty Acid and Cholesterol Content of Pakistani Water Buffalo Breeds

Present study evaluates the milk fatty acid (FA) composition and cholesterol content of two main Pakistani dairy breeds water buffaloes, i.e. Kundi and Nili-Ravi (n = 25 for each breed). The buffaloes were housed together and received the same diet. The results show a significant variation (P < 0.05) in the FA content of the two breeds. The milk fat of Kundi buffalo was found to contain significantly lower (P < 0.05) amount of saturated fatty acid content than Nili-Ravi buffaloes (66.96 and 69.09 g/100 g). Determined mean monounsaturated fatty acid (MUFA) contents (27.62 vs. 25.20 g/100g) and total trans fatty acids (3.48 vs. 2.48) were significantly elevated (P < 0.05) in the milk fat of Kundi buffaloes. Amount of fat and conjugated linoleic acid content was higher (P = 0.04) in Kundi buffalo as compared to Nili-Ravi buffaloes (7.00 vs. 7.78 g /100g and 0.80 vs. 0.71g / 100g), while cholesterol content was not different among both breeds ranging from 8.89 – 10.24 mg /dl. Present studies show that in future genetic selection programs along with altered buffalo nutrition may be able to result in optimum levels of various fatty acids in milk