A paper platform for colorimetric determination of aluminum hydrochloride in antiperspirant samples

Abstract A simple, fast, low-cost, portable, and eco-friendly method using a spot test on a paper platform, together with diffuse reflectance spectroscopy, was developed and validated for the quantification of aluminum hydrochloride, a potential neurotoxic agent, in antiperspirant samples. The determination of aluminum hydrochloride was performed at a wavelength of 615 nm, by measuring consumption of the purple colorimetric reagent Alizarin S, due to reaction with aluminum. The linear range was from 10.0 to 125.0 mg L −1 and could be described by the equation: A R  = 0.4479 − 0.002543 C Al (R = 0.999). The limits of detection (LOD) and quantification (LOQ) were 3.06 and 10.2 mg L −1 , respectively. The method was specific, accurate, and repeatable, with relative standard deviation (RSD)