Octylamine as environment friendlier colorimetric detection probe for hazardous 2,4,6-Trinitrophenol from wastewater samples

The precise detection of hazardous 2,4,6-Trinitrophenol (TNP) is essential for the environment and human health. TNP is used as a precursor in whistling fireworks in ammunition, mining, agriculture and is a hazardous environmental pollutant generated from leather, chemical, and dye industries. Exploring rapid and low-cost approaches for the detection and quantification of TNP has attracted many scientists nowadays. The proposed chemosensor utilizes the concept of dispersive liquid-liquid micro-extraction coupled with a UV-visible spectrophotometer for its sensing at the ultra-trace level. Significant changes based on intramolecular interactions followed by a distinct color change to orange-red from yellow in the presence of TNP is an attractive feature for the present study. The successive addition of TNP shows ultra-trace sensitivity (3.9831 μA μM-1 cm-1) at detection limit (LOD) of 0.0015 ± 0.03 μM (S/N = 3), a linear range of 0 μM-70 μM, and a response time of <5 min. Different types of real samples such as creatinine testing kit reagent, fireflies crackers, serum, and water samples were used and recovery of TNP was calculated by spiking the known concentration of the standard analyte. The obtained recovery was 93.6-103.6% with RSD range of 1.6-4.53% (n = 3) in different samples. The analytical performance of the colorimetric Chemoprobe in terms of its recovery, linearity range, and limit of detection offers an excellent platform for monitoring hazardous TNP. The results show that the proposed colorimetric chemosensor is easy to use, low-cost, environmentally friendly and offers an easily observable visual color change. Based on these features, the chemosensor can be used for large-scale applications for the detection of TNP in water and other samples.