Validated multi‐drug determination using liquid chromatography with tandem mass spectrometry for the evaluation of a commercial drug disposal product

Currently, there are limited effective means of drug disposal for consumers, and this creates a gateway to illicit use and environmental contamination. Here, we evaluated the efficacy of a new drug disposal product, composed from a slurry of activated carbon, which claims to sequester up to 100% of a drug's active ingredient when the loading capacity is not exceeded, making it safe to dispose in landfill. High‐performance liquid chromatography with tandem mass spectrometry was applied to quantify as many as 24 drugs (opiates, barbiturates, statins, amphetamine, and benzodiazepine drugs) in the residual solvent solution from the product. Calibration curves were established in the concentration ranges of 0.25–7.0 μg/mL and showed good linearity. The limits of detection varied from 0.001 to 0.02 μg/mL, depending on the drug. Accuracy ranged from 80 to 111% for quality control samples, with a few minor exceptions. Precision overall varied between 0.2 to 12.7%. In sample bottles tested, where active ingredient of the loaded drug was below the maximum sorption capacity stated on the label, 98 to >99.9% of the active ingredient was sequestered. Percent active ingredient adsorbed was slightly lower in bottles loaded in excess of label specifications.     

Advanced TMAH and TMAAc thermochemolysis–pyrolysis techniques for molecular characterization of size-separated fractions from aquatic dissolved organic matter

The structural similarities and differences between the original DOM and the eight size fractions separated were studied in detail with the pyrolysis technique in combination with gas chromatography and mass spectrometry (Py-GC-MS) using two alkylating reagents: TMAH (tetramethylammonium hydroxide), to find both esterified and free carboxylic acids; and TMAAc (tetramethylammonium acetate), to specify only free carboxylic acids. A statistical analysis of the original multidimensional TMAH and TMAAc pyrograms disclosed that the overall structural compositions of the five most important size fractions, accounting for 84% of the original DOM, greatly resembled each other. The remaining three minor size fractions were not classified as homogeneous associations, but they also contained the same total, covalently bound and free carboxylic acid species as the other size fractions and the original DOM mixture, thus representing some kind of intermediate forms. This fundamental outcome strongly supports the opinion that the native dissolved humic-like macromolecules resemble supramolecular associations of smaller molecular size moieties with similar structural functionalities. The concentrations of free aliphatic and aromatic dicarboxylic acids in the DOM solution were so low that their effects on the potential formation of multiply charged ions in electrospray ionization-MS (ESI-MS) studies are likely insignificant.     

Interfacial p-n heterojunction of polyaniline-nickel ferrite nanocomposite as room temperature liquefied petroleum gas sensor

In this work, we introduce polyaniline–nickel ferrite (PANI-NF) nanostructured composite to detect liquefied petroleum gas (LPG) at room temperature. The composite synthesized by relatively simple method of in-situ chemical polymerization was structurally characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The presence of characteristic absorption bands of both PANI and NF in the FTIR spectrum of the composite with small shifts confirmed interfacial interaction of PANI with NF. The XRD studies also confirmed interfacial interaction between PANI and NF in the composite and its crystalline nature with an average crystallite size of 20 nm. Highly agglomerated granular porous morphology favourable for LPG adsorption was revealed by SEM image of the composite. The TEM image of the composite clearly showed nanosized NF particles embedded in PANI matrix. The LPG sensing performance of the composite at room temperature was tested using a film prepared by depositing the composite on an ordinary glass substrate by cost-effective spin coating technique. The maximum sensing response of the composite was found to be 57% at 700 ppm of LPG, with a response time of 50 s and a recovery time of 200 s. The composite was found to be stable for a period of one month. The sensing mechanism has been discussed on the basis of formation of interfacial p–n heterojunction barrier.     

大气压氮氧等离子体射流灭活表面大肠杆菌及其发射光谱分析研究

研究了氮氧源大气压等离子体射流对表面大肠杆菌灭活作用,分析了氮氧源大气压等离子体射流的光谱性质。结果表明,在放电电压为6.8kV,气体流速为4L?min?1,处理3min时,氮氧比为1:4的大气压等离子体射流对大肠杆菌的灭活率达到98.4%,接近氧气源大气压等离子体射流灭菌效果。通过大气压等离子体射流发射光谱(OES)分析了氮氧源大气压等离子体射流中活性物质,进而解释大肠杆菌微生物灭活机理,认为NO?γ、OI、?OH等活性物质在表面大肠杆菌灭活过程中起到了重要作用。这将为大气压氮氧等离子体射流在环境卫生、微生物灭活等方面的应用研究提供实验基础和技术支持。     

污泥内层和外层胞外聚合物的三维荧光光谱特性研究

运用三维荧光光谱技术对污泥LB-EPS和TB-EPS的荧光特性进行了研究.实验结果表明,在污泥LB-EPS和TB-EPS中都有三个明显的荧光峰,分别为Peak B(λex/λem=270～280 nm/345～360 nm),Peak C(λex/λem=330～340 nm/410～430 am)和Peak D(λex/λem=390 nm/450～470 nm).其中Peak B为类蛋白荧光(Protein-like)、Peak C为可见区类富里酸荧光(Visible fulvic-like)、Peak D为类腐殖酸荧光(Humic-like).从各荧光峰的荧光强度来分析,LB-EPS和TB-EPS中的主要成分都为类蛋白,然后依次为富里酸和腐殖酸.浓度和pH值对污泥LB-EPS和TB-EPS的三维荧光特性都有很大的影响,但影响程度略有区别,表明作为外层的胞外聚合物,LB-EPS表现出与TB-EPS不全相同的化学结构.     

棉籽化学成分的分析

采用索氏提取法对棉籽中棉籽油进行了提取,以气相色谱-质谱联用仪进行了分析,分离鉴定出10种脂肪酸,占棉籽油总量的99.52%。并对其主要成分进行了鉴定,主要化学成分为:棕榈酸26.68%,亚油酸66.05%。用蒸馏-萃取法提取棉花籽中挥发性物质,测得棉籽挥发油的量为0.80%,用GC/MS法从棉籽挥发油中分离并确定出16种化学成分。用峰面积归一化法通过化学工作站数据处理系统,得出各化学成分在挥发油中的质量分数。其中主要成分为:石竹烯量高达33.27%。     

食品接触材料检测技术新进展

由食品接触材料中高关注物质迁移而导致的食品安全问题已成为当今社会的重点关注领域.这些有意添加物和非有意添加物具有种类复杂、无标准谱图和标准品等特点,使其识别鉴定、定量检测与安全评估面临着众多技术挑战.发展快速、准确、灵敏的食品接触材料检测技术,实现高关注迁移物的准确定量检测是食品接触材料安全研究和管理的关键.该文简要介...     

ZSM-5分子筛催化剂上液化石油气低温芳构化制取高辛烷值汽油

 考察了反应温度、空速、压力、临氢条件以及催化剂的水热处理条件对液化石油气在ZSM-5分子筛催化剂上低温芳构化制取高辛烷值汽油反应性能的影响. 结果表明,反应温度和空速对催化剂的催化性能有明显影响,提高反应温度有利于提高芳烃的选择性,同时芳烃中的苯、甲苯和C10+芳烃含量增加; 增大进料空速,催化剂的芳构化性能下降,芳烃中的重组分增加,二甲苯中对二甲苯含量增大. 催化剂的水热处理温度升高,其初始芳构化活性下降,而催化剂经过适当的水热处理和系统中氢气的存在均可提高催化剂催化芳构化反应的稳定性.     

中国车前草挥发性化学成分分析

用同时蒸馏 萃取装置(SDE)提取中国车前草的挥发性物质,测得车前草挥发油质量分数为2.79%,用GC MS法从车前草的挥发油中分离确认出20种化学成分,占挥发油总量的95.08%。用峰面积归一化法通过化学工作站数据处理系统得出各化学成分在挥发油中的质量分数。     

酸枣果肉中挥发性化学成分的提取及分析

报道了用蒸馏-萃取法和同时蒸馏-萃取法提取酸枣果肉中挥发性物质,测得两种方法提取的酸枣果肉挥发油含量分别为1．80％和2．30％。用GC／MS法从酸枣果肉挥发油中分别分离并确定出43种和28种化学成分,分别占酸枣果肉挥发油总检出量的95．62％和94．88％。用峰面积归一化法通过化学工作站数据处理系统,得出各化学成分在挥发油中的相对百分含量。