Biohybrid adsorbent for the preconcentration of lead and its determination in fruit juices by electrothermal atomic absorption spectrometry.

Abstract

Fruit juices are one of the most non-alcoholic beverages consumed in the world. Essential elements and other nutrients present in fruit juices play an important role in human well-being. However, fruit juices may also contain potentially toxic elements at trace levels, causing health risks. The objective of this work was to develop an analytical methodology based on the preconcentration of lead using a new biodegradable hybrid material composed of Rhodococcus erythropolis AW3 bacteria and Brassica napus hairy roots. The biodegradable hybrid material was implemented in an online solid phase extraction system for the determination of lead in fruit juices by electrothermal atomic absorption spectrometry. Effects of critical parameters on lead retention were studied. Under optimal experimental conditions, extraction efficiency higher than 99.9% and an enrichment factor of 62.5 were achieved. The dynamic capacity of the biodegradable hybrid material was 36 mg/g, which favored the reuse of the column to at least 8 biosorption-desorption cycles. The limit of detection and quantification for preconcentration of 5 mL of sample were 5.0 and 16.5 ng/L lead, respectively. The relative standard deviation was 4.8% (at 1 µg/L lead and n = 10). The developed method was suitable to be applied for lead determination in different types of fruit juices.