A high-performance liquid chromatography (HPLC) method for the determination of azadirachtin (A and B) residues in bovine muscle has been developed. Azadirachtin is a neutral triterpene and chemotherapeutic agent effective in controlling some pest flies in horses, stables, horns and fruit. The actual HPLC method uses an isocratic elution and UV detection. Liquid-liquid extraction and solid-phas...

Projective Nonnegative Matrix Factorization (PNMF) has demonstrated advantages in both sparse feature extraction and clustering. However, PNMF requires users to specify the column rank of the approximative projection matrix, the value of which is unknown beforehand. In this paper, we propose a method called ARDPNMF to automatically determine the column rank in PNMF. Our method is based on autom...

A new fast screening method has been developed for the analysis of organochlorine pesticides in water that takes less than 10 min to perform and has detection limits of the order of 10 ng l21. Pesticide extraction was achieved by solid-phase microextraction and the separation was performed using a micro-bore (0.1 mm) capillary column. A laboratory-built cryotrap system was used to focus the ana...

urinary 1-hydroxypuren (1-ohp) is commonly used as a major metabolite and biological indicator of the overall exposure to polycyclic aromatic hydrocarbons (pahs). for evaluation of human exposure to such compounds, biological monitoring is an essential process, in which, preparation of samples is one of the most time-consuming and error-prone aspects prior to chromatographic techniques. in this...

A major bottleneck for metagenomic sequencing is rapid and efficient DNA extraction. Here, we compare the extraction efficiencies of three magnetic bead-based platforms (KingFisher, epMotion, and Tecan) to a standardized column-based extraction platform across a variety of sample types, including feces, oral, skin, soil, and water. Replicate sample plates were extracted and prepared for 16S rRN...

Essential oil components were extracted from Lavandula angustifolia (Lavender) flowers using pressurized fluid extraction (PFE). A Box-Behnken design was used to optimize the effective extraction variables. The chemical composition of extracted samples was analyzed by gas chromatograph-flame ionization detector column. For achieving maximum % extraction yield the temperature, pressure, and dyna...

A gas chromatographic (GC) method was developed for the determination of sucrose monoesters of fatty acids (mono-SuE) and sucrose acetate isobutyrate (SAIB) in food additive premixes. Mono-SuE and SAIB fractions were prepared by column chromatography with either a C8 or a silica gel solid-phase extraction column. The mono-SuE fraction was acetylated and applied to a wide-bore GC column (0.53 mm...

Grape anthocyanins not only play an important role in the colour quality of red wines but they also have many beneficial effects on human health, e.g., reduction of coronary heart disease incidence, or anticarcinogenic and antioxidant properties. Therefore, a rapid and efficient extraction technique prior to chromatographic analysis is of primary interest. Pressurised Fluid Extraction (PFE) pre...

an experimental study of the phase inversion behavior of liquid-liquid dispersion has been conducted in a spray extraction column for systems of toluene / water, n-hexane/water, ccl4/water, toluene /water + glycerol (25 % wt), toluene + ccl4 (25 % wt) / water and toluene / acetic acid (5 % wt)/water. the effects of physical properties, mass transfer and column geometry on phase inversion have b...