Determination of trace amounts of lead in mussels by flow-injection flame atomic-absorption spectrometry coupled with on-line minicolumn preconcentration

Abstract

A minicolumn packed with poly(aminophosphonic acid) chelating resin incorporated in an on-line preconcentration system for flame atomic-absorption spectrometry was used to determine ultratrace amounts of lead in mussel samples at microg L(-1) level. The preconcentrated lead was eluted with hydrochloric acid and injected directly into the nebulizer for atomization in an air-acetylene flame for measurement. The performance characteristics of the determination of lead were: preconcentration factor 26.8 for 1 min preconcentration time, detection limit (3sigma) in the sample digest was 0.25 microg g(-1) (dry weight) for a sample volume of 3.5 mL and 0.2 g sample (preconcentration time 1 min), precision (RSD) 2.3% for 25 microg L(-1) and 2.0% for 50 microg L(-1). The sampling frequency was 45 h(-1). The method was highly tolerant of interferences, and the results obtained for the determination of lead in a reference material testify to the applicability of the proposed procedure to the determination of lead at ultratrace level in biological materials such as mussel samples.

Evaluation of Pb-Spec® for flow-injection solid-phase extraction preconcentration for the determination of trace lead in water and wine by flame atomic absorption spectrometry

“…However, preconcentration in the batch mode can be time-and reagent-consuming, with a risk of sample contamination or analyte loss, whereas automated techniques such as flow-injection (FI) are rapid, economical, and may require only small volumes [6,7]. FI sample introduction has been coupled with FAAS for preconcentration and matrix removal [8], and several solid-phase extraction (SPE) procedures have been developed for the determination of lead [9][10][11][12][13]. The most commonly used procedure involves lead complexation with DDC, followed by retention on C-18 silica and Amberlite XAD-7 [5,12,13], though various other extractants, including silica treated with Aliquat 336 [4], alumina [14], cellulose [15], and Chromosorb 102 [16], have been used to retain the uncomplexed cation.…”

Continuous ultrasound-assisted extraction of iron from mussel samples coupled to a flow injection-atomic spectrometric system

“…5 Conversion of the analyte to the liquid phase is possible by wet acid extraction, microwave-assisted extraction, or acid or alkaline ultrasound-assisted extraction. [6][7][8] Flow injection (FI) digestion procedures involving microwave energy present some advantages over their manual counterparts, such as smaller digestion times, easy digestion of complex matrices and the use of a closed vessel (decreasing the losses of volatile analytes and increasing personal safety). Due to these advantages, microwaves have been used on-line in different studies for the determination of trace metals.…”