Two methods for the determination of tetrodotoxin (TTX) in marine biota have been developed and validated using ultra-performance LC coupled to triple quadrupole MS. The direct analysis of TTX is completed in one method, while the other method detects the dehydration product of TTX after reaction with base. The methods were validated in a single-laboratory trial and used to test Paphies australis (pipi) samples collected from Whangapoua, New Zealand during April 2011. Pa. australis is a commonly eaten species of bivalve that was found to contain TTX at levels up to 0.80 mg/kg in this study. The methods exhibited recoveries ranging from 94 to 120%, and the within laboratory reproducibility ranged from 6 to 27% for Pleurobranchaea maculata (grey-side gilled sea slug) and bivalve matrixes. Use of the method using a dehydration step showed no evidence of TTX analogs in any of the samples.

The protein binding of ketoprofen enantiomers was investigated in human plasma at physiological pH and temperature by ultrafiltration. 14C-labelled (RS)-ketoprofen was synthesized and purified by high-performance liquid chromatography and utilized as a means of quantifying the unbound species. In vitro studies were conducted with plasma obtained from six healthy volunteers. The plasma was spiked with (R)-ketoprofen alone, (S)-ketoprofen alone, and (RS)-ketoprofen in the enantiomeric concentration range of 1.0 to 19.0 micrograms/ml. The plasma protein binding of ketoprofen was nonenantioselective. At a racemic drug concentration of 2.0 micrograms/ml the mean (+/- SD) percentage unbound of (R)-ketoprofen was 0.80 (+/- 0.15)%. The corresponding value for (S)-ketoprofen, 0.78 (+/- 0.18)%, was not statistically different (P greater than 0.05). At this racemic drug concentration (2.0 micrograms/ml) the percentage unbound of each enantiomer was unaffected (P greater than 0.05) by the presence of the glucuronoconjugates of ketoprofen (10 micrograms/ml) in plasma. At clinically relevant concentrations, the plasma binding of ketoprofen did not exhibit enantioselectivity or concentration dependence nor was the binding of either enantiomer influenced by its optical antipode (P greater than 0.05).

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The derivative of glycine, 8-phenylmenthyl N-Boc-2-bromoglycinate 2 reacts with unsaturated stannanes to give unsaturated amino acid derivatives with high diastereoselectivity.

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