An accurate, sensitive, precise, rapid, isocratic reversed phase HPLC (RP-HPLC) method for the determination of doxycycline hyclate in bulk drug and in tablets, and also in spiked human urine, was developed and validated. The best separation was achieved on a 250 mm × 4.0 mm i.d, 5.0 μm particle size C8 reversed phase thermo column with acetonitrile-potassium dihydrogenorthophosphate buffer (pH...

Based on the nitrogenous base or quaternary ammonium moiety in isoxsuprine hydrochloride (ISX), two highly accurate and selective titrimetric methods are proposed f or the determination of ISX in spiked human urine, injection and tablets. Non aqueous titration (Method A) involves removal of protonated amine using mercuric acetate for enhanced basic nitrogen prior to titration with perchloric ac...

This is the first report on use of two visible spectrophotometric methods for the determination of bupropion hydrochloride (BUPH) in pharmaceuticals and spiked human urine. Bupropion is a second-generation antidepressant agent which is also used in the management of smoking cessation. The methods are based on charge transfer complexation reaction of bupropion base (BUP) as n-electron donor with...

Human urine is a potential alternative fertilizer for agriculture. However, its usage is associated with a risk of spreading pharmaceutical residues to fields. The individual and combined behavior of carbamazepine and ibuprofen was investigated by GC/MS analysis in a greenhouse experiment using ryegrass fertilized with pharmaceutical-spiked urine. Only carbamazepine could be detected in soil, r...

A very simple, rapid and highly sensitive fluorimetric method for the determination of difhmisal in serum and urine is described. The method is based on the formation of a ternary complex between ditlunisal, Tb3+ and EDTA in alkaline aqueous solutions. This complex exhibits very intense terbium ion luminescence with a main emission maximum at 546 nm when excited at 284 mn. Optimum conditions fo...

We have developed an enzyme-nanoparticle sensor array where the sensitivity is amplified through enzymatic catalysis. In this approach cationic gold nanoparticles are electrostatically bound to an enzyme (beta-galactosidase, beta-Gal), inhibiting enzyme activity. Analyte proteins release the beta-Gal, restoring activity and providing an amplified readout of the binding event. Using this strateg...

A method for the determination of trace amounts of the herbicide oxadiazon was developed using headspace solid-phase microextraction (HS-SPME), gas chromatography-mass spectrometry (GC-MS) and selected ion monitoring. It was applied to determine oxadiazon in ground water, agricultural soil, must, wine and human urine samples. To determine oxadiazon in liquid samples, a response surface methodol...

In the present work, a practical method that combines excitation-emission matrix fluorescence with a second-order calibration method based on an alternating trilinear decomposition (ATLD) algorithm was developed in order to simultaneously and directly determine the contents of warfarin (WAR) and aspirin (ASA) in human plasma and urine samples, even in the presence of unknown interferences. With...

Urinary 1-hydroxypyrene is frequently used as a major metabolite and biological indicator of the overall exposure to polycyclic aromatic hydrocarbons. In this study, solid phase extraction was appropriately conditioned with regard to sample pH, sample concentration, loading flow rate, elution solvent, washing solvent, sample volume and sorbent mass. Octadecyl silica cartridge (C<su...

Humans are exposed to arsenic (As) in the environment, in both organic and inorganic forms, and it has been widely demonstrated that the inorganic arsenic species (arsenate and arsenite) are the main toxic ones being drinking water one of the main sources of exposure worldwide. Urinary arsenic level is the recommended biomarker for assessing human exposure risks. Absorbed inorganic arsenic is m...