SCREENING FOR DRUGS IN SERUM AND URINE BY LC / ESI / CID-MS AND MS / MS WITH LIBRARY SEARCHING
A mass spectra library using in-source collision induced dissociation (ESI/CID) as well as a MS/MS library with product ion spectra of ca. 500 drugs have been developed with a triple-quadrupole ionspray mass spectrometer. For the ESI/CID MS library single quadrupole mode and for the MS/MS library triple-quadrupole mode were used. The libraries have been used for general-unknown screening and for identification of drugs and metabolites in serum and urine.
Extraction of benzoylecgonine (cocaine metabolite) and opiates (codeine and morphine) from urine samples using the Zymark RapidTrace.
The Zymark RapidTrace automated solid-phase extraction system has been evaluated for use in the urine drug-testing laboratory. Methods for cocaine metabolite (benzoylecgonine) and opiates (codeine and morphine) are described and evaluated. The linearity, precision, accuracy, recovery, and carryover statistics of these analytical protocols are presented. The advantages of extraction using the RapidTrace instead of solid-phase extraction with the manual vacuum manifold or liquid-liquid extraction methods are described.
l-Phenylalanine dehydrogenase from Brevibacterium sp. for production of l-phenylalanine by reductive amination of phenylpyruvate
SummaryFor production of l-phenylalanine the reductive amination of phenylpyruvate, catalyzed by phenylalanine-dehydrogenase was examined. To reach high levels and a sufficient stability of the inducible intracellular enzyme, growth conditions of Brevibacterium sp. are optimized. For continuous production of l-phenylalanine in an enzyme membrane reactor, the kinetic parameters of the partially purified enzyme are determined.In continuous production a space time yield of 37.4 g l-Phe l-1 d-1 can be reached.By means of the measured kinetic parameters and simultaneous calculation of the mass balances of all reaction components the behaviour of the reactor can be simulated. For certain conditions the multi-enzyme-system shows multiple steady-states.