Trace molybdenum determination in drinking waters by USN-ICP-OES after solid phase extraction on ethyl vinyl acetate turnings-packed minicolumn

ESCUDERO, L., GIL, R.A., GÁSQUEZ, J.A., OLSINA, R.A., MARTINEZ, L.D.

ATOMIC SPECTROSCOPY

Francis&Taylor

Año: 2008 vol. 29 p. 21 - 26

0195-5373

This study presents the developmentof a novel on-line preconcentrationmethod forinorganic molybdenum by flowinjection solid-phase extractionwith detection by inductivelycoupled plasma optical emissionspectrometry and ultrasonic nebulization(SPE-USN-ICP-OES). Thismethod employs a minicolumnfilled with ethyl vinyl acetateturnings as the adsorbent material.This system was applied tothe on-line preconcentration anddetermination of molybdenum inwater samples with good selectivityand reproducibility; molybdenumwas retained on theminicolumn without furthercomplexation.The time required for the preconcentrationof a 20-mL sample,injection/data acquisition, andconditioning was about 5.0 minutes,resulting in a samplethroughput of 12 samples perhour. A 300-fold total enhancementfactor for this sample volumewas obtained with respectto the molybdenum determinationby ICP-OES without preconcentration.The precision for six replicatemeasurements of a solution containing20 μg L-1 Mo was 3.5%relative standard deviation, calculatedat peak height. The limit ofdetection (3s) was 0.04 μg L-1.This method was successfullyapplied to trace molybdenumdetermination in drinking watersamples and in a certified referencematerial (Metals in NaturalWaters, NIST CRM 1643e).