A field method for quantifying ammonium picrate and picric acid in soil

Abstract

A simple field method for the determination of ammonium picrate and picric acid in soil was developed. Picric acid is a strong acid with a pKa ϭ 0.80, and is colorless when dissolved in an organic solvent, whereas its anion ( picrate) is bright yellow. Picric acid and picrate ions were extracted from undried soil by shaking with acetone; any picric acid extracted was rapidly converted to picrate in the wet acetone. Picrate was extracted from the acetone soil extracts by passing the solutions through a solid-phase anion exchanger to remove interferences. Acidified acetone was used to convert the picrate to picric acid and elute it from the ion exchanger. The absorbance of the solution at 400 nm was measured; then the picric acid was converted to the colored picrate ion by diluting the eluent with water. Absorbance at 400 nm was measured again and the concentration of picrate was obtained from the difference in the absorbance measurements, corrected for dilution. The method detection limit is 1.3 g g Ϫ 1 of soil. Field-contaminated soils were assayed, and the results compared favorably to those from HPLC analyses in the range of 10 -4400 g g Ϫ 1 . The method is simple to use, can be implemented under field conditions, and complements on-site methods for TNT, RDX, and 2,4-DNT.

Selective Detection of Trinitrophenol by Amphiphilic Dimethylaminopyridine-Appended Zn(II)phthalocyanines at the Near-Infrared Region

“…29 However, the aqueous phase detection of TNP becomes an imperative aspect for the design of potential sensors because of its high water solubility (∼14 g/L at 20 °C) and low octanol–water partition coefficient (log K ow = 1.6). 30 To the best of our knowledge, the design of explosive chemical sensors in aqueous medium at the NIR region is very limited. The fluorescent sensors at the NIR region has significant advantages over the visible region because of lower photo damage and reduced light scattering and can effectively avoid background interference to enhance the selectivity and sensitivity.…”

Rational Design of a Bifunctional, Two‐Fold Interpenetrated ZnII‐Metal–Organic Framework for Selective Adsorption of CO2 and Efficient Aqueous Phase Sensing of 2,4,6‐Trinitrophenol

“…Among the NACs like, 2,4,6‐trinitrophenol (TNP), 2,4,6‐trinitrotoluene (TNT), 2,4‐dinitro toluene (DNT), nitrotoluene (NT), 1,3‐dinitrobenzene (DNB), nitrobenzene (NB), and 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX), TNP has the highest explosive power and has been identified as a toxic pollutant . Its extensive usage in the preparation of fireworks and the dyes and leather industries, leads to its release into the environment causing the contamination of water and soil, resulting in unpleasant effects on human health, such as, liver or kidney damage, irritation to skin/eye, and damage to the respiratory system, etc . Therefore, its efficient detection in aqueous media has attracted considerable attention.…”

A Fluorescent 1,3‐Diaminonaphthalimide Conjugate of Calix[4]arene for Sensitive and Selective Detection of Trinitrophenol: Spectroscopy, Microscopy, and Computational Studies, and Its Applicability using Cellulose Strips

“…Apart from its explosive nature when stored in metallic containers, TNP also pollutes the environment. Because of its widespread utility, TNP causes severe health hazards such as damaging the respiratory system, causing skin irritation, and so on, whereas its partially reduced form, that is, picramic acid, is ten times more mutagenic than that of simple TNP 16. 17 Thus, there exists a dire need to detect TNP in a variety of samples 18–26.…”