a rapid isocratic method of high performance liquid chromatography system (hplc) with a glassy carbon working electrode of electrochemical detector is set up for quantitative detection of  trace amount of nitrite ion (no2¯) in aqueous protein containing cell lysate, cell media, plasma, serum, urine and other body fluids. the solid extraction  reversed phase cartridges (sep-pak) are used for dep...

INTRODUCTION [(18)F]BAY94-9172 (Florbetaben) (Compound 8) is a positron emission tomography (PET) tracer that is currently in Phase III study for in vivo mapping of fibrillar amyloid β as a pathological hallmark for Alzheimer's disease. This work reports new methods for the synthesis of [(19)F]BAY94-9172 and its two different precursors and radiosynthesis of [(18)F]BAY94-9172 with the two precu...

A method for determination of tricyclazole in water using solid phase extraction and high performance liquid chromatography (HPLC) with UV detection at 230 nm and a mobile phase of acetonitrile:water (20:80, v=v) was developed. A performance comparison between two types of solid phase sorbents, the C18 sorbent of Supelclean ENVI-18 cartridge and the styrene-divinyl benzene copolymer sorbent of ...

We describe a precise, specific method for measunng 24,25dihydroxyvitamin D3 in human serum. A 2-mL serum sample is extracted with acetonitrile and passed through a Sep-Pak C-18 cartridge. The sample is further purified by “highperformance’ liquid chromatography under isocratic conditions on a normal-phase column (Radial-Pak silica-gel cartridge), then subjected to a protein-binding assay. The ...

In this study, a new clean up method was developed for the routine multiresidue determination of organochlorine pesticide residues in honey. The analytical procedure requires sample extraction with methanol, followed by a clean up step through a C18 Sep-Pak cartridge. Finally, pesticides are eluted with hexane. The determination of organochlorine pesticide residues was performed by capillary ga...

A sensitive liquid chromatograph/tandem mass spectrometric technique (LC/MS/MS) was applied to determine aliphatic and aromatic carbonyl compounds in ambient air. Traces of the carbonyl compounds were sampled by passing through a Sep-Pak DNPH-silica cartridge. Their derivatives were thus eluted with acetonitrile, separated by reversed-phase liquid chromatography and determined by quadrupole tan...

In this liquid-chromatographic method for determination of urinary oxalate, interfering compounds in the urinary samples were eliminated before chromatography by passage through a preparative C18 mini-column (Sep-pak cartridge, Waters Associates). In the reversed-phase system tetrabutyl ammonium was included as a counter ion to enhance the retention of oxalate. The pH of the mobile phase was ke...