Modification of triple quadrupole linear ion trap mass spectrometer for laser-induced dissociation on cationic peptides

This journal supplement is the 59th ASMS Conference ProgramPoster Presentation - Peptides: Ion Activation/Dissociation: ThP 452The 59th ASMS Conference on Mass Spectrometry and Allied Topics, Denver, CO., 5-9 June 2011. In Journal of The American Society for Mass Spectrometry, 2011, v. 22 suppl. 1, p. 179, abstract no. ThP 45

Laser-induced dissociation of singly cationic peptides at 193nm with a modified triple quadrupole linear ion trap mass spectrometer

Poster presentation - Peptides: Ion Activation/Association Strategies: WP 762This journal supplement is the 60th ASMS Conference ProgramThe 60th ASMS Conference on Mass Spectrometry and Allied Topics, Vancouver, Canada, 20-24 May 2012. In Journal of The American Society for Mass Spectrometry, 2012, v. 23 suppl. 1, p. S153, abstract no. WP 76

On-line solid-phase enrichment coupled to packed reactor flow injection analysis in a green analytical procedure to determine low levels of folic acid using fluorescence detection

<p>Abstract</p> <p>Background</p> <p>Analysis of folic acid (FA) is not an easy task because of its presence in lower concentrations, its lower stability under acidic conditions, and its sensitiveness against light and high temperature. The present study is concerned with the development and validation of an automated environmentally friendly pre-column derivatization combined by solid-phase enrichment (SPEn) to determine low levels of FA.</p> <p>Results</p> <p>Cerium (IV) trihydroxyhydroperoxide (CTH) as a packed oxidant reactor has been used for oxidative cleavage of FA into highly fluorescent product, 2-amino-4-hydroxypteridine-6-carboxylic acid. FA was injected into a carrier stream of 0.04 M phosphate buffer, pH 3.4 at a flow-rate of 0.25 mL/min. The sample zone containing the analyte was passed through the CTH reactor thermostated at 40°C, and the fluorescent product was trapped and enriched on a head of small ODS column (10 mm x 4.6 mm i.d., 5 μm particle size). The enriched product was then back-flush eluted by column-switching from the small ODS column to the detector with a greener mobile phase consisting of ethanol and phosphate buffer (0.04M, pH 3.4) in the ratio of 5:95 (v/v). The eluent was monitored fluorimetrically at emission and excitation wavelengths of 463 and 367 nm, respectively. The calibration graph was linear over concentrations of FA in the range of 1.25-50 ng/mL, with a detection limit of 0.49 ng/mL.</p> <p>Conclusion</p> <p>A new simple and sensitive green analytical procedure including on-line pre-column derivatization combined by SPEn has been developed for the routine quality control and dosage form assay of FA at very low concentration level. The method was a powerful analytical technique that had excellent sensitivity, sufficient accuracy and required relatively simple and inexpensive instrumentation.</p