The Basis of a Greener Analytical Chemistry

Ion mobility spectrometry as a fast analytical tool in benzalkonium chloride homologs determination

A novel procedure is proposed for the determination by ion mobility spectrometry (IMS) of C₁₂, C₁₄ and C₁₆ benzalkonium chloride (BAC) homologs. The proposed method requires minimum sample treatment and the measurement was made in less than one minute. A high sensitivity was obtained for BAC determination by IMS with limit of detection values from 37 to 69µgL^-1. Accuracy of the proposed methodology was evaluated through the analysis of aqueous and alcoholic samples spiked with BAC at concentration levels from 0.002% to 20% (w/v), providing recovery values from 91% to 104%. BAC was determined in sanitary alcohols, nasal sprays, postharvest products, algaecides, and treated swimming pool water. Results obtained by the proposed IMS methodology were statistically comparable to those provided by a liquid chromatography-ultraviolet (LC-UV) reference methodology. The Green Certificate evaluation of the proposed IMS methodology provided 91 score points in the Eco-Scale as compared with 77 for LC-UV method.

Green near-infrared determination of copper and mancozeb in pesticide formulations

A green analytical procedure has been successfully developed for the simultaneous determination of copper and mancozeb in phytosanitary products. The method is based on different direct measurements of diffuse reflectance near-infrared (DR-NIR) spectra. Accuracy of the method has been evaluated by comparison of the obtained copper and mancozeb concentrations with those provided by reference methodologies based on titrimetric procedures. The average relative prediction error was 0.7 and 1.6 % for copper and mancozeb, respectively. The evaluation of the greenness of the DR-NIR procedure provided 100 points, which is the maximum value in the Green Certificate ranking, because of the absence of consumed reagents and waste generation and energy consumption lower than 0.1 kWh.