Determination of cocaine and benzoylecgonine in nails by liquid chromatography-electrospray ionization-tandem mass spectrometry

Determination of porphyrins in oral bacteria by liquid chromatography electrospray ionization tandem mass spectrometry

Biofilms in the oral cavity can be visualized by fluorescence and a common assumption is that the endogenously produced porphyrins in certain bacteria give rise to this fluorescence. Porphyrin content in oral bacteria has been sparingly investigated, and non-selective detection techniques such as utilizing the Soret fluorescence band of porphyrins are often used. In the present study, a quantit...

Determination of glimepiride in human plasma by liquid chromatography-electrospray ionization tandem mass spectrometry.

A sensitive and specific high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS-MS) method has been developed at our center for the determination of glimepiride in human plasma. After the addition of the internal standard, plasma samples were extracted by liquid-liquid extraction technique using diethyl ether. The compounds were separated on a prepa...

Determination of naloxone and nornaloxone (noroxymorphone) by high-performance liquid chromatography-electrospray ionization- tandem mass spectrometry.

A highly sensitive method was developed to measure naloxone and its metabolite nornaloxone in human plasma, urine, and human liver microsomes (HLM). Naltrexone-d(3) and oxymorphone-d(3) were used as respective internal standards. Solid-phase extraction, using mixed mode extraction columns and 0.1 M phosphate buffer (pH 5.9), was combined with high-performance liquid chromatography interfaced by...

Creatinine Determination in Urine by Liquid Chromatography-electrospray Ionization-tandem Mass Spectrometry Method.

Creatinine determination in urine is used to estimate the completeness of the 24-h urine collection, compensation for variable diuresis and as a preliminary step in protein profiling in urine. Despite the fact that a wide range of methods of measuring creatinine level in biofluids has been developed, many of them are adversely affected by interfering substances. A new liquid chromatography-tand...

chromatography–electrospray ionization tandem mass spectrometry