Disposable optical sensor for Al(III) ions determination by coupled colorimetric solid-phase extraction-reflectance spectroscopy in leachates from cookware, antacids and hygienic care products

• Published in: Talanta (Oxford) 2019-12, Vol.205, p.120102-120102, Article 120102
• Main Authors: Castañeda-Loaiza, V., Díaz-de-Alba, M.I., Granado-Castro, M.D., Galindo-Riaño, M.D., Casanueva-Marenco, M.J.
• Format: Article
• Language: English
• Subjects: Aluminium; Aluminum - analysis; Antacids; Antacids - analysis; Colorimetric solid-phase extraction; Colorimetry - methods; Deodorants - analysis; Diffuse reflectance spectroscopy; Drug Contamination - prevention & control; Hydrazones - chemistry; Leachates from cookware; Limit of Detection; Optical sensor; Polystyrenes - chemistry; Pyridoxal - analogs & derivatives; Solid Phase Extraction - instrumentation; Solid Phase Extraction - methods; Solvents - chemistry; Spectrophotometry - methods; Water - analysis; Water Pollutants, Chemical - analysis
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2019.06.102

A disposable and miniaturised optical sensor based on colorimetric solid-phase extraction has been designed using poly(styrene-divinylbenzene) membrane disks modified with the colorimetric reagent pyridoxal salicyloylhydrazone to determine the aluminium concentration in aqueous solutions. The extraction of Al(III) ions by the reagent immobilised onto a disk allows the quantification directly on the adsorbent surface by a miniature portable reflectance spectrometer with an optical fibre at 434 nm. The optimisation of the sensing system was carried out by a fractional factorial design 33−1 considering the extraction pH, amount of ligand immobilised onto the disk and time of immobilisation as experimental factors. The linear dynamic range of the sensor response ranged from 0.18 to 2 mg L−1 Al(III) with a detection limit of 0.18 mg L−1 (n = 10), being the precision of 6.3% for 1 mg L−1 Al(III) (n = 10, confidence level of 95%). The proposed method was successfully applied to the analysis of aluminium in leachates from cookware, antacids and hygienic care products, as contribution to the concern about aluminium as a known systemic toxicant at high doses. [Display omitted] •A disposable optical sensor for Al(III) determination has been designed.•The sensor is based on the coupling of C-SPE and DRS techniques.•The Al sensor involves simple instrumentation, easy handle and low cost.•The sensor can be used how alarm system in common contaminated products by Al(III).•The environmentally friendly sensor can be applied to leachates of cookware.