Extraction , 205?. Separation solid-phase


Trace residue analysis of compounds in various matrices is an essential process for evaluation of different exposures to such toxicants, in which, preparation of samples is one of the most time-consuming and error-prone aspects prior to chromatographic analyses. A comparative study of sample preparation was performed to preconcentrate urinary 1-hydroxypyrene (1-OFIP) as a major metabolite and biological indicator of the overall exposure to polycyclic aromatic hydrocarbons (PAFIs) generated by various industrial and environmental processes. To perform this study, solid phase extraction (SPE) was optimized with regard to sample pFI, sample concentration, loading flow rate, elution solvent, washing solvent, sample volume, elution volume, and sorbent mass. The present approach proved that, 1-OFIP could be efficiently retained on CIS sorbent based on specific interaction. Further study employed methanol to extract the analyte from spiked urine. Along with, a nonclassic form of liquid-liquid extraction (LEE) also was optimized with regard to solvent type, solvent volume, extraction temperature, mixing type, and mixing duration. The results showed that, 1-OFIP could be relatively well extracted by methanol at optimum time of 2 minutes based on moderate specific interaction. At the developed conditions, obtained recovery of SPE was 99.96%, while, the EEE extraction recovery did not exceed 87.3% and also, based on applied sample volume, the limit of detection (EOD) achieved by SPE was 0.02 p.g/1 showing at least ten times less than that of EEE. The procedures were validated with three different pools of spiked urine samples showed a good reproducibility over six consecutive days as well as six within-day experiments for both developed methods as suitable results were obtained for CV% (less than 3.1% for SPE and between 2.8% and 5.05% for EEE). In this study, a high performance liquid chromatography (HPEC), using reverse-phase column was used. The mobile phase was methanol/water am at constant flow rate of 0.8 ml/min and a fluorescence detector was used, setting at 242 nm and 388 nm. Although the recovery and EOD were obtained for SPE method shows more efficiency, such results for EEE is also relatively efficient and can be applied for majority of similar studies. However, there is a significant difference between the obtained recoveries of SPE and EEE (P<0.05), showing that, SPE is superior.  [c.378]


Modern analytical chemistry (2000) -- [ c.212 , c.213 , c.567 ]