Development of a gas chromatographic-mass spectrometric drug screening method for the N-dealkylated metabolites of fentanyl, sufentanil, and alfentanil

A sensitive, specific urinary assay for fentanyl, sufentanil, and alfentanil based on their N-dealkylated metabolites is described. Norfentanyl, norsufentanil-noralfentanil, and 2H5-norfentanyl are synthesized and characterized by standard analytical techniques. Derivatization of these secondary amines to yield the pentafluorobenzamides produces stable products with good gas chromatographic properties and unique, high-mass fragments in their mass spectra. These properties are utilized to develop a drug screening procedure based on gas chromatography-mass spectrometry to detect these major metabolites in human urine. The metabolites are isolated from urine samples by a liquid-liquid extraction procedure. The method allows for detection of metabolite concentrations as low as 0.3 ng/mL.     

Choosing a user interface development tool

Software developers face many difficult decisions when building new applications, not the least of which is the design of the graphical user interface. The answer to one question-is it better to use a GUI development tool or build it manually?-is relatively straightforward. Today's tools offer several benefits that manual coding does not. Because these tools often provide a simple graphical interface for developing displays, nonprogrammers and human factors engineers can contribute their expertise. Also, if the schedule permits, a tool can be used to build prototypes throughout the development cycle; some tools even provide a test/prototype mode for testing displays without compiling and executing the entire application. And finally, end users can evaluate each prototype and provide feedback, increasing their satisfaction with the final product