A fast method for the measurement of metabolites of pyrene in urine was improved by HPLC with fluorescence detector using "heart-cut" technique. This method can quantify the total amount of pyrene metabolites corresponding to glucuronic acid and sulfate conjugates as well as free 1-OH-Py. The hydrolyzed biological fluid was directly injected into the chromatographic system, via a column-switching system. Pre-treatment and analysis were performed within 0.5 and 9 min, respectively. Enzymatic hydrolysis has been optimized to not exceed 2 h. The best response function, in the 0.2-10 ng/mL range, is the linear regression, bringing simplicity, good accuracy, and low LOQ. The intra- and interday precision values were inferior to 1 and 2%, respectively. The proposed method provided a simple, convenient, and practical procedure to determine the level of the main urinary pyrene metabolites in biological samples.

A s y s t e m a t i c s t u d y of t h e i n f l u e n c e o f several chromatographic p a r a m e t e r s upon a d s o r p t i o n o f t e t r a l k y l ammonium i o n s on r e v e r s e d -p h a s e s h a s been made. R e s u l t s show t h a t o r p a n i c s o l v e n t c o n t e n t i n mobile p h a s e , t e t r a l k y l ammonium h y d r o p h o b i c i t y and t e t r a l k y l ammonium c o n c e n t r a t i o n i n e l u e n t are t h e most i n f l u e n t v a r i a b l e s . A mathematical e x p r e s s i o n t o c a l c u l a t e t h e adsorbed i o n c o n c e n t r a t i o n f o r d i f f e r e n t combinations of t h e s e v a r i a b l e s i s deduced. R e s u l t s from t h i s s t u d y c a n be. a p p l i e d i n I o n P a i r Reversed-Phase Chromatography t o c a l c u l a t e column e q u i l i b r a t i o n t i m e s , f o r s e t t i n g , p -a d i e n t e l u t i o n s e p a r a t i o n methods and for t h e s t u d y o f r e t e n t i o n mechanisms.

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