短脉冲激光作用下丙酮液池沸腾现象的瞬态观测

本文对短脉冲激光作用下试件表面的温度变化和丙酮液体汽泡行为进行了瞬态观测,研 究了激光参数和细小金属颗粒等因素对丙酮液体沸腾行为的影响。结果表明：激光参数中,脉宽是 影响温度曲线和汽泡行为的主要因素,随着激光脉宽增大,大汽泡的长大时间和脱离直径减小;汽 泡长大速度与常规沸腾时的完全不同,没有出现等温生长阶段,在激光脉冲后很长时间内汽泡长大 速度快速增大;试件表面覆盖细小金属颗粒后,沸腾过程变得非常剧烈。     

Simple and automatic determination of aldehydes and acetone in water by headspace solid-phase microextraction and gas chromatography-mass spectrometry

We describe a simple and automatic method to determine nine aldehydes and acetone simultaneously in water. This method is based on derivatization with 2,2,2-trifluoroethylhydrazine (TFEH) and consecutive headspace-solid-phase microextraction and gas chromatography-mass spectrometry. Acetone-d(6) was used as the internal standard. Aldehydes and acetone in water reacted for 30 min at 40°C with TFEH in a headspace vial and the formed TFEH derivatives were simultaneously vaporized and adsorbed on polydimethylsiloxane-divinylbenzene. Under the established condition, the method detection limit was 0.1-0.5 μg/L in 4 mL water and the relative standard deviation was less than 13% at concentrations of 0.25 and 0.05 mg/L. This method was applied to determine aldehydes and acetone in 5 mineral water and 114 surface water samples. All mineral water samples had detectable levels of methanal (24.0-61.8 μg/L), ethanal (57.7-110.9 μg/L), propanal (11.5-11.7 μg/L), butanal, pentanal (3.3-3.4 μg/L) and nonanal (0.3-0.4 μg/L). Methanal and ethanal were also detected in concentration range of 2.7-117.2 and 1.2-11.9 μg/L, respectively, in surface water of 114 monitoring sites in Korea.     

室内空气中甲醛浓度的测定

目的为了快速准确的测定高校室内空气中甲醛浓度。方法采用乙酰丙酮分光光度法,对计算机房、物理实验室、化学实验室三个房间的甲醛浓度进行了测定分析。结果相对于化学实验室来说,计算机房的甲醛浓度多了0.77倍;物理实验室的甲醛浓度比化学实验室的多了0.98倍。结论室内空气质量可能会受新房对甲醛的释放时间以及室内新家具的存放时间影响;乙酰丙酮分光光度法具有简便、易控制、成本低等优点,可以广泛使用于普通室内甲醛浓度的测定。     

Recent methods for the determination of peroxide-based explosives

In the last few years, the need to determine peroxide-based explosives in solid samples and air samples has resulted in the development of a series of new analytical methods for triacetonetriperoxide (TATP, acetone peroxide) and hexamethylenetriperoxidediamine (HMTD). In this review, after a short introduction describing the state of the art in the field, these new analytical methods are critically discussed. Particular emphasis is placed on spectroscopic and mass spectrometric methods as well as on chromatographic techniques with selective detection schemes. The potential of these methods to analyse unknown solid samples that might contain one or more of the explosives and to analyse peroxide-based explosives in air is evaluated.     

Asymmetric cross-aldol reaction of isatin and ketones catalyzed by crude earthworm extract as efficient biocatalyst

ABSTRACT

The asymmetric cross-aldol reaction of simple ketones (acetone, cyclohexanone) with isatin derivatives in the presence of crude extract from earthworms as green and effective biocatalyst proceeds easily in MeCN/H₂O (1:1) as solvent to afford 3-hydroxy-2-oxindoles derivatives. Ten compounds were synthesized in high yields (62–88%) and moderate ee (29–42%). Structure of the synthesized compounds has been characterized on the basis of NMR spectra and CHN analysis. The ee of the obtained compounds was determined by chiral phase HPLC analysis.     

基于电喷雾电离质谱(ESI-MS)的丙酮稳定同位素标记对N-糖链的相对定量分析方法的研究

建立了一种基于电喷雾电离质谱的丙酮稳定同位素标记对N-糖链进行相对定量的研究方法. 与传统的PNGase F酶水解N-糖链的方法不同,采用非特异性蛋白酶Pronase E对N-糖蛋白进行处理,使N-糖蛋白被酶解为带有一个氨基酸的糖氨酸（Glycan-Asn）,为N-糖链引入了一个氨基活性基团,然后用丙酮对氨基进行标记. 用d₀/d₆丙酮对Ribo B标准糖蛋白的Pronase E酶解产物进行标记,考察了4对d₀/d₆丙酮标记的Glycan-Asn（Man₅～Man₈-Asn）在电喷雾电离质谱中的线性、动态范围以及重现性. 结果表明,在10倍动态范围内,相对定量方法有良好的线性关系（R=0.9981）和重现性（CV<8.7%）. 并将建立的方法应用于不同含量的鸡卵清白蛋白中,进一步验证了该方法的可行性. 研究结果表明,该方法能准确分析样品中N-糖链的含量,对不同样品中N-糖链进行相对定量. 该方法成本低廉,后处理方法简单方便,适于微量样品通量化分析,对差异糖组的研究有一定的意义.     

气相色谱—傅里叶变换红外光谱联用技术用于分析工业丙酮中的杂质

本文提出了一种气相色谱－傅里叶变换红外光谱联用技术分析工业丙酮杂质成份的方法，该方法采用ＦＦＡＰ毛细管柱，柱长２５ｍ，内径０．２５ｍｍ，膜厚０．３３μｍ，占总面积１．１６％的１２种杂能够被分离和鉴定。     

2-(E-2-苯乙烯基)喹啉的合成

以苯甲醛为原料在碱性条件下与丙酮缩合得苄叉丙酮（1），1与邻氨基苯甲醛发生Friedlaender缩合反应得到新的目标产物2－（E－2－苯乙烯基）喹啉(2),产率81％。     

The Photochemistry of Acetone: The Primary Decomposition of Acetone and Biacetyl Yields

In the photolysis of acetone at 265nm at 27°C the quantum yield of biacetyl has been determined to be 0.34 and the primary decomposition yield is evaluated to be about 0.68. The fraction of triplet acetone decomposed into methyl and acetyl radicals is estimated to be 0.14 at 313nm. The acetyl radicals undergo reaction to form biacetyl 50 times faster than decomposition to methyl radicals and carbon monoxide.