In this automated procedure for quantifying biotinidase activity in human serum, a manual colorimetric method that measures conversion of the enzyme's artificial substrate N-biotinyl p-aminobenzoate was modified for use with a Technicon AutoAnalyzer II. The intra-run replicate precision (CV) was 2.1% and the day-to-day CV was 4.6% for quality-control sera. Results were linearly related to biotinidase activity in serum over the complete range of clinically relevant values, 0.2 to 11.0 U/L. Moreover, results of the automated assay were not significantly different from those of the manual assay. Because the automated procedure is faster and more precise, we recommend it for population-based studies and some screening studies.

The application of a new automated workstation for conducting solution-phase reactions in parallel during chemical process development is described. The fully automated reactor−analysis system is capable of reagent/reactant addition, temperature and agitation control, and sample extraction/quench/injection for online HPLC analysis. Both precision and accuracy of the fluidic delivery and sampling systems were measured through the use of standard ultraviolet chromophore solutions in conjunction with HPLC analysis. Agitation efficiency was evaluated using a phase-transfer catalysis reaction known to be rate-dependent on stirring frequency. Chemistry cases examined included several single and multistep reactions studied to identify the best reagent/solvent combinations (screening) and optimal levels of continuous variables such as temperature, concentration, and stoichiometry (optimization). A multistep route to a chiral substituted imidazolidin-2-one was developed from initial route scouting through reaction condition screening, optimization, and scale-up. Reactions performed included alkylation, reduction, oxidation, reductive amination, displacement, and cyclization.

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