Üzer Ayşem, Yalçın Uğur, Can Ziya, Erçağ Erol, Apak Reşat
Analytical Chemistry Division, Chemistry Department, Faculty of Engineering, Istanbul University, 34320 Avcilar, Istanbul, Turkey.
Analytical Chemistry Division, Chemistry Department, Faculty of Engineering, Istanbul University, 34320 Avcilar, Istanbul, Turkey.
Talanta. 2017 Dec 1;175:243-249. doi: 10.1016/j.talanta.2017.06.049. Epub 2017 Jun 20.
Pentaerythritol tetranitrate (PETN) is the nitrate ester of pentaerythritol, used as an energetic and filling material for military and civilian purposes and rarely for terrorist actions. As there is no reliable nano-colorimetric method for PETN assay, we developed an indirect method based on the determination of nitrite, obtained by reduction of nitrate derived from the alkaline hydrolysis of PETN with HO. We colorimetrically determined the final product, nitrite, by both conventional Griess reaction and a recently developed gold nanoparticle-4-aminothiophenol-N-(1-naphthyl)-ethylenediamine (AuNP-4-ATP+NED) method. Nitramines (RDX and HMX), if present, could be degraded by alkaline hydrolysis, without affecting PETN. The analytical performance characteristics of the developed assays as molar absorptivity (ε), limits of detection (LOD) and quantification (LOQ) were: ɛ=1.06×10 L mol cm, LOD=0.03mgL and LOQ=0.11mgL for indirect Griess method; ɛ=1.9×10Lmol cm; LOD=0.12mgL and LOQ=0.4mgL for AuNP-4-ATP+NED method. Both methods were applied to a 1:1 (w/w) mixture of PETN and TNT (corresponding to the composition of military explosive 'Pentolite'). In order to eliminate the interference from TNT, the Meisenheimer anion of TNT formed in alkaline medium was retained on a strongly basic anion exchange resin column. As PETN had a very low solubility in water, common soil ions could be eliminated by prewashing the sample with water, or in acetone-water mixtures, Ca, K, Cl, SO, and NO could be tolerated at equal (1:1) mass ratios. Soil nitrates and nitrites, at a mass ratio of 50:1, could be separated from PETN with the aid of their insolubilities in acetone and of their retention affinity toward a strongly basic anion-exchange resin. The developed method was statistically validated against a reference GC-MS method.
季戊四醇四硝酸酯（PETN）是季戊四醇的硝酸酯，用作军事和民用的含能材料及填充材料，很少用于恐怖活动。由于目前尚无可靠的纳米比色法测定PETN，我们开发了一种间接方法，该方法基于对亚硝酸盐的测定，亚硝酸盐是通过用HO还原PETN碱性水解产生的硝酸盐而获得的。我们通过传统的格里斯反应和最近开发的金纳米颗粒-4-氨基硫酚-N-（1-萘基）-乙二胺（AuNP-4-ATP+NED）方法比色测定最终产物亚硝酸盐。如果存在硝胺（RDX和HMX），它们可通过碱性水解降解，而不影响PETN。所开发方法的分析性能特征，如摩尔吸光系数（ε）、检测限（LOD）和定量限（LOQ）分别为：间接格里斯法的ε=1.06×10 L·mol⁻¹·cm⁻¹，LOD=0.03mg/L，LOQ=0.11mg/L；AuNP-4-ATP+NED法的ε=1.9×10⁴L·mol⁻¹·cm⁻¹，LOD=0.12mg/L，LOQ=0.4mg/L。两种方法都应用于PETN和TNT的1:1（w/w）混合物（对应于军用炸药“彭托利特”的组成）。为了消除TNT的干扰，在碱性介质中形成的TNT的迈森海默阴离子保留在强碱性阴离子交换树脂柱上。由于PETN在水中的溶解度非常低，可以通过用水预洗样品来消除常见的土壤离子，或者在丙酮-水混合物中，Ca、K、Cl、SO₄²⁻和NO₃⁻可以以相等（1:1）的质量比被容忍。土壤中的硝酸盐和亚硝酸盐，质量比为50:1时，可借助它们在丙酮中的不溶性以及它们对强碱性阴离子交换树脂的保留亲和力与PETN分离。所开发的方法相对于参考GC-MS方法进行了统计学验证。
