A new alkyne functionalized pterin derivative was synthesized through a reaction of 7-chloropterin with propargyl alcohol in the presence sodium hydride. The purity and chemical structure compound validated by NMR (1H, 13C) spectroscopy, Mass (APCI source) spectrometry, elemental analysis, X-ray crystallography. title may be further exploiting yne moiety, for instance, using click chemistry. no...

Liquid chromatography coupled with atmospheric pressure chemical ionization (APCI) ion trap mass spectrometry (ITMS) is applied to atmospheric aerosol relevant carbonyls. Characterization of positive and negative ion detection mass spectra are presented for 24 model compounds analyzed in their underivatized and O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) oxime forms. The addition of PF...

Chromatographic behavior of co-eluted compounds from un-extracted drug-free plasma samples was studied by LC-MS and LC-MS/MS with positive APCI. Under soft gradient, total ion chromatogram (TIC) consisted of two major peaks separated by a constant lower intensity region. Early peak (0.15-0.4 min) belongs to polar plasma compounds and consisted of smaller mass ions (m/z<250); late peak (3.6-4.6 ...

Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances. However, some compounds do not show enough sensitivity in LC/MS and soft-ionization methods commonly used in LC/MS, such as electrospray ionization (ESI) and atmospheric pressure chemical i...

Liquid chromatography coupled to atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) mass spectrometry (MS), in parallel, was used for simultaneous detection of bovine milk sphingolipids (BMS). APCI-MS mass spectra exhibited mostly ceramide-like fragment ions, [Cer-H(2)O+H](+) and [Cer-2H(2)O+H](+), which were used to identify individual molecular species of BMS ac...

2,4,6-Trinitrotoluene (TNT) transformation by the yeast strain Yarrowia lipolytica AN-L15 was shown to occur via two different pathways. Direct aromatic ring reduction was the predominant mechanism of TNT transformation, while nitro group reduction was observed to be a minor pathway. Although growth of Y. lipolytica AN-L15 was inhibited initially in the presence of TNT, TNT transformation was o...

To simultaneously quantify and profile the complex mixture of short-, median-, and long-chain CPs (SCCPs, MCCPs, and LCCPs) in Australian sewage sludge, we applied and further validated a recently developed novel instrumental technique, using quadrupole time-of-flight high resolution mass spectrometry running in the negative atmospheric pressure chemical ionization mode (APCI-qTOF-HRMS). Withou...

A simple and specific liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) assay method has been developed and fully validated for the simultaneous quantification of cefixime (CX) and clavulanic acid (CA) in human plasma. Analytes and internal standard were extracted from human plasma by a solid phase extraction technique using a Sam prep (3 mL, 100 mg) ...

A liquid chromatographic method is described for the simultaneous determination of tributyltin (TBT) and the hydroxylated intermediate 4-hydroxybutyldibutyltin (OHBuDBT). Separation was achieved in reverse phase mode on a cyanopropyl-bonded silica column under a gradient elution. Various organic solvents and additives were tested and the optimum composition of the mobile phase contained methano...