Recent advances in sensitive analytical techniques have enabled the analysis of drugs in unconventional biological materials such as sweat. In a study conducted during a heroin maintenance program, 14 subjects had sweat patches applied, then received intravenously two or three doses of heroin hydrochloride ranging from 80 to 1000 mg/day. The sweat patch was applied 10 min before the first dosag...

Adrenergic drugs for growth promotion have been outlawed in European meat production; however, molecules such as Ractopamine and Zilpaterol are licensed for feeding swine and cattle in the United States, Mexico, and South Africa. Analysis of bovine retinal extracts has recently shown considerable extension in the detection period following withdrawal. Previous studies demonstrated that residual...

A study has been made as a function of temperature of the phase transformation of water and ice in two samples of mesoporous silica gel with pore diameters of approximately 50 A. One sample was modified by coating with a layer of trimethylchlorosilane, giving a predominantly hydrophobic internal surface, whereas the unmodified sample has a hydrophilic interface. The pore structure was character...

A gas chromatography-mass spectrometry (GC-MS) method using the standard addition methodology was developed for the determination of glucuronolactone (GL) and glucuronic acid (DGuA) in four beverages categorized as detoxification, recovery, or energy drinks. The method features a precolumn derivatization step with a combination of BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide) and TMCS (trim...

As an attempt to elucidate the factor(s) responsible for the poor performance of a copper(II)-phthalocyanine aminopropylsilica gels (CU-PCSD) column for HPLC, the silanol and/or amino groups remaining on Cu-PCSD were endcapped with trimethylchlorosilane (TMCS) or N-trimethylsilylimidazole (TMSI). The trimethylsilylated Cu-PCS(D)S (Cu-PCSD-TMCS and -TMSI) were investigated concerning their perfo...

A gas chromatographic method has been developed for the assay of fluvastatin sodium (FLU). FLU was silylated with N,Obis(trimethylsilyl)trifluoroacetamide-1% trimethylchlorosilane at 90 oC for 30 min and analysed in a DB-1 column by capillary gas chromatograph with a flame ionization detector. The method was validated. The assay was linear over the concentration range at 10.0 to 50.0 mg mL. The...

The superhydrophobic silica coating has a great performance of self-cleaning which can be applied in the field of energy saving, anti-icing, drag reduction, etc. In this paper, Trimethyltrimethoxysilane (MTMS) /Trimethylchlorosilan (TMCS) superhydrophobic silica coating with two-layer structure was dip-coated. Atomic force microscope (AFM) images show that the surface morphology of MTMS/TMCS si...

Gas chromatography–mass spectrometry (GC–MS) has been investigated for identification of bisphenol A (BPA) at ppb levels in biological samples. Initially a limit of detection (LOD) of 600 ppb BPA was established by direct selected-ion monitoring (SIM) GC–MS. Next, standard solutions of BPA and extracts of powdered milk were derivatized with two different reagents – N,O-bis-(trimethylsilyl)trifl...

A study is conducted to determine the amino acid, fatty acid, and carbohydrate content of breadfruit using high-performance liquid chromatography (HPLC) and gas chromatography (GC). An HPLC method is used for the determination of amino acids and fatty acids in breadfruit. Representative amino acid samples are derivatized with phenylisothiocianate and the resulting phenylthiocarbamyl derivatives...