On-line complexation/preconcentration system for the determination of leadin wine by inductively coupled plasma-atomic emission spectrometry with ultrasonic nebulization

An on-line lead preconcentration and determination system implemented with inductively coupled plasma-atomic emission spectrometry (ICP-AES) with ultr asonic nebulization (USN) in association with flow injection was studied. F or the preconcentration of lead, a Pb-quinolin-8-ol complex was formed on-l ine at pH 6.8 and retained on Amberlite XAD-16 resin. The lead was removed from the microcolumn by countercurrent elution with nitric acid. A total en hancement factor of 225 was obtained with respect to ICP-AES with pneumatic nebulization (15.0 for USN and 15.0 for the column). The detection limit f or Pb for the preconcentration of a 10 mL wine sample was 0.15 mug/L. The p recision for 10 replicate determinations at a Pb level of 25 mug/L was a re lative standard deviation of 2.5%, calculated from the peak heights obtaine d. The calibration graph obtained by using the preconcentration system for lead was linear with a correlation coefficient of 0.9995 for levels near th e detection limit up to greater than or equal to 1000 mug/L. The method was successfully applied to the determination of lead in wine samples.