Jonas Björklund

Large-volume programmed-temperature vaporiser injection for fast gas chromatography with electron capture and mass spectrometric detection of polybrominated diphenyl ethers

A large volume injection fast-GC-MS method has been developed, optimized and evaluated for the determination of polybrominated diphenyl ethers, including the decabrominated diphenyl ether (BDE-209). The programmed-temperature vaporiser injection parameters, temperature programming of the GC oven, and the physical dimensions of the narrow bore GC column were investigated to find the optimal operating conditions for the analysis. Depending on parameter settings the yield of the PBDEs and particularly BDE-209, varies significantly. Volumes up to 125 microl were successfully injected and a fast GC separation was performed, with retention times as short as 6.4 min for the last eluting compound, BDE-209. In a pilot study an air sample, collected at an electronics dismantling facility, was analyzed. Low-resolution mass spectrometry in electron capture negative ion mode was used for detection. Nine BDE congeners, including BDE-209, were identified and quantified.

Automated amino acid determination by high-performance liquid chromatography with 2-(9-anthryl)ethyl chloroformate as precolumn reagent

Abstract A fully automated HPLC method for the determination of amino acids in protein hydrolysates has been developed, using 2-(9-anthryl)ethyl chloroformate and precolumn derivatization. This UV sensitive reagent reacts rapidly with both primary and secondary amines at room temperature to form stable carbamate derivatives. The reaction conditions have been thoroughly investigated. A complete separation of protein hydrolysates is accomplished within 40 min. The results are compared to those of the well known 9-fluorenylmethyl chloroformate method. Detection limits for UV and fluorescence detection were found to be 0.5 pmol and 0.06 pmol, respectively.