A solid device based on doped hybrid composites for controlling the dosage of the biocide N-(3-aminopropyl)-N-dodecyl-1,3-propanediamine in industrial formulations

•Colorimetric composite device based on NQS immobilized in PDMS–TEOS–SiO2 NPs.•Application to control the biocide N-(3-aminopropyl)-N-dodecyl-1,3-propanediamine.•Green, simple and rapid approach for samples analysis from different industries.•Quantitative analysis by diffuse reflectance and digital image analysis.

A colorimetric composite device is proposed to determine the widely used biocide N-(3-aminopropyl)-N-dodecyl-1,3-propanediamine (ADP).This sensing device is based on a film of 1,2-Naphthoquinone-4-sulfonate (NQS) embedded into polydimethylsiloxane–tetraethylortosilicate–SiO2 nanoparticles composite (PDMS–TEOS–SiO2NPs). Semiquantitative analysis can be performed by visual inspection. Digitalized image or diffuse reflectance (DR) measurements can be carried out for quantitative analysis. Satisfactory detection limit (0.018%, w/v) and relative standard deviations <12% were achieved. The proposed device has been applied for the determination of ADP in detergent industrial formulations with recovery values between 80% and 112%. The method has been successfully validated, showing its high potential to control and monitor this compound because the device is easy to prepare and use, robust, portable, stable over time and cost effective. This device allows a green, simple and rapid approach for the analysis of samples without pretreatment and does not require highly trained personnel. These advantages give the proposed kit good prospects for implementation in several industries.

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