高效液相色谱法测定地表水中的微囊藻毒素-LR

对地表水中的微囊藻毒素-LR进行高效液相色谱法（HPLC）测定,采用V乙醇：V水（含0．1％三氟乙酸）=45：55为流动相,微囊藻毒素．LR在ODS色谱柱上获得理想的分离效果。采用含0．1％三氟乙酸的乙醇溶液在样品前处理提取中获得较高的提取效率,通过优化前处理及检测条件,有效地去除了干扰,获得了简便、安全、有效的检测效果。     

花生及其制品中多种霉菌毒素残留同时测定方法

利用液相色谱-质谱联用（LC-MS／MS）建立了花生及其制品中多种霉菌毒素包括黄曲霉毒素（B1,B2,G1,G2）、赭曲霉毒素A、伏马毒素B1、脱氧雪腐镰刀菌烯醇、T-2毒素、HT-2毒素及玉米赤霉烯酮的同时测定方法。样品经PBS溶液和甲醇-水溶液提取,提取液经稀释、过滤后,用免疫亲和柱净化,通过淋洗去除免疫亲和柱上的杂质,随后用洗脱液过柱,将目标物分离下来,氮吹干后定容。以液相色谱-质谱／质谱测定,外标法定量。方法的检出限黄曲霉毒素B1为0．0005mg／kg,黄曲霉毒素B2,G1,G2为0．001mg／kg,赭曲霉毒素A为0．002mg／kg,伏马毒素B1为0．020mg／kg,脱氧雪腐镰刀菌烯醇为0．050mg／kg,T-2毒素为0．010mg／kg,HT-2毒素为0．010mg／kg,玉米赤霉烯酮为0．002mg／kg。在样品中添加检出限水平的毒素混标溶液,加标回收率为72．35％-97．82％,测定结果的相对标准偏差为8．95％～18．41％（n=10）.     

固相萃取高效液相色谱法测定水中痕量-微囊藻毒素

微囊藻毒素是有害的蓝藻水华释放的有毒代谢物,对人类及环境具有很大危害性。建立了固相萃取－高效液相色谱测定水中痕量藻毒素的方法。该法对两种常见微囊藻毒素MC－LR、MC－RR的检测限为0．02－0．05μg/L,线性定量范围为0．1－50μg/L。应用该法分析了天然水样,表明方法具有实用性。     

荧光色谱-柱后光化学衍生法测定食品中的黄曲霉毒素B1

采用免疫亲和层析柱吸附食品样品中的黄曲霉毒素B1,以荧光色谱-柱后光化学衍生法测定食品中黄曲霉毒素B1的含量。样品用甲醇-水溶液（体积比为7：3）混合,均质器高速搅拌提取,经免疫亲和层析柱纯化后,通过LachromC18色谱柱进行分离,以甲醇一水溶液（体积比为45：55）作为流动相,荧光检测器激发波长为360nm、发射波长为420nm,外标法定量。黄曲霉毒素B,的质量浓度在1～20ng／mL范围内与色谱峰面积线性关系良好,相关系数r=0．9998,检出限为0．1gg／kg。在3个添加水平下,样品的加标回收率在88．5％～97．9％之间,相对标准偏差均小于3％（n=6）。该方法操作简单、定量准确,可用于食品中黄曲霉毒素B．的定量定性检验。     

高效液相色谱法检测水体中微囊藻毒素

建立了高效液相色谱检测水体中微囊藻毒素(Microcystins,MCs)的方法.选择XAD-2树脂为富集树脂,采用四氯化碳-10%乙醇-10%丙酮连续淋洗,获得较好的杂质去除效果,采用90%甲醇可以将树脂柱上的MCs完全洗脱.HPLC采用V(0.1% TFA):V(甲醇)=42: 58混合溶液为流动相进行等度洗脱,MC-RR和 MC-LR取得较好分离效果,回收率均达到90%以上.水样富集2000倍后,方法的检出限为0.05 μg/L.本方法操作简便、灵敏度高、检测速度快.     

聚碳酸亚丙酯洗涤工段洗涤液组分分析

采用气质联用法对聚碳酸亚丙酯（PPC）生产工艺中洗涤工段洗涤液组分进行定性及定量分析。分析结果表明洗涤液中的杂质主要有1-甲氧基-2．丙醇、2-甲氧基-1-丙醇、碳酸二甲酯、二丙撑二醇、碳酸丙烯酯。1次洗涤液中含环氧丙烷32．34％,含甲醇58．74％;4次洗涤液中含环氧丙烷10．61％,含甲醇89．01％。随着洗涤次数的增加,样品中环氧丙炕含量减小,甲醇含量增大。     

固相萃取-高效液相色谱法测定地表水中微囊藻毒素

提出了固相萃取-高效液相色谱法测定水中微囊藻毒素的方法.水样经减压过滤后,过C18反相固相萃取柱富集浓缩,用20%(体积分数)甲醇溶液淋洗,以1 mL·min-1的流速,用纯甲醇将微囊藻毒素从固相萃取柱上洗脱下来,氮吹浓缩后,用0.05 mol·L-1磷酸盐缓冲液作流动相,与甲醇以体积比为40比60进行淋洗,紫外检测波长为238 nm,用此方法对两种微囊藻毒素MC-LR、MC-RR的线性范围为0.25～10.0 mg·L-1,测定限(10S/N)均为0.05 μg·L-1,回收率在76.2%～96.5%之间.     

Ce/Zr/Al类水滑石的合成、表征及其吸附性能研究

本研究对Ce/Zr/Al三元类水滑石材料去除微囊藻毒素(MC)的潜在应用进行了探索。采用共沉淀法合成了碳酸根型Ce/Zr/Al三元类水滑石,通过XRD、IR等手段对样品进行了测试和表征。合成的类水滑石用于吸附MC,并详细研究了其对MC的吸附性能。结果显示,控制反应条件为温度80℃,M3+/M4+摩尔投料比为1∶1,pH为8.5,合成的Ce/Zr/Al三元类水滑石对MC具有较高的吸附性能,对微囊藻毒素LR(MC-LR)最大吸附量可达178μg/g,对MC-LR和微囊藻毒素RR(MC-RR)的吸附效率均大于70%,吸附性能明显高于硅胶等常用吸附剂。这些研究数据表明Ce/Zr/Al三元类水滑石对去除水体中微囊藻毒素具有潜在的应用价值。     

免疫亲和层析-液质联用法检测蓝藻中的微囊藻毒素

应用自制的微囊藻毒素(microcystin,MC)免疫亲和层析柱为净化工具,建立了固相萃取柱富集、免疫亲和层析柱净化、液质联用法检测蓝藻样品中MC的方法.结果显示:只用固相萃取柱富集,会残留大量杂质,干扰MC(尤其是MC-LR)的测定结果.而用免疫亲和层析柱净化能有效去除藻样中的杂质,排除干扰,通过液质联用法定量,能准确测定藻样中的微囊藻毒素-RR(MC-RR)和-微囊藻毒素-LR(MC-LR).方法的检出限为2.5 μg/L; 线性范围为5～500 μg/L; MC-RR和MC-LR平均回收率高于84%; 相对标准偏差低于5%.     

在线固相萃取–液相色谱法测定水中3种微囊藻毒素

建立了在线固相萃取–液相色谱法测定水中3种微囊藻毒素的方法。采用Acclaim PA Cartridge在线固相萃取小柱(10 mm×4.3 mm,5μm),以KH2PO4缓冲溶液–甲醇为富集流动相,进样体积为10 m L。以KH2PO4缓冲溶液–乙腈为洗脱流动相,采用二极管阵列检测器进行检测,检测波长为238 nm。微囊藻毒素MC–LR,MC–RR在0.1~10.0μg/L范围内线性关系良好,MC–YR线性范围则为0.1~5.0μg/L,相关系数r2不小于0.998,3种微囊藻毒素MC–LR,MC–RR,MC–YR的检出限均为0.1μg/L(S/N=3),水源水加标回收率为96.9%~105.4%,测定结果的相对标准偏差为3.55%~6.46%(n=12)。该方法适用于水源水及饮用水中3种微囊藻毒素的快速测定。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

化学计量中不确定度评定研究进展

测量不确定度是表征合理地赋予被测量之值的分散性的参数。本文针对化学计量不确定度评定基础模型仅适用于线性模型、概率分布为正态分布或缩放位移t分布等局限,介绍了近年来不确定度评定的研究热点:蒙特卡罗方法(Monte Carlo Method,MCM),不确定度评定的来源、评定概念、评估方法及其发展过程,扩大了测量不确定度评定与表示的适用范围。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.