硅烷化GC/MS法同时测定卷烟中的糖、1,2-丙二醇和甘油

建立了硅烷化衍生化法结合气相色谱/质谱(GC/MS)法同时测定卷烟中1,2-丙二醇、甘油和糖类物质含量的分析方法。样品以N,N-二甲基甲酰胺(DMF)和N,O-双(三甲基硅烷基)三氟乙酰胺(BSTFA)为提取溶剂和衍生化试剂,于70℃衍生化反应30 min,采用DB-5MS色谱柱(60 m×0.25 mm×0.25μm),用GC/MS分析测定1,2-丙二醇,甘油、果糖、葡萄糖和蔗糖的含量。方法线性关系良好,检出限为0.04~2.85 mg/g,定量限为0.13~9.51 mg/g,平均加标回收率为90.3%~114.4%,相对标准偏差小于9.1%。方法适合于卷烟样品中1,2-丙二醇、甘油和糖类物质的同时测定。     

在线加压溶剂微提取-湍流色谱-高效液相色谱法同时测定管花肉苁蓉中3种苯乙醇苷

建立了在线加压溶剂微提取-湍流色谱-高效液相色谱(online PLME-TFC-HPLC)法,并将其应用于管花肉苁蓉中松果菊苷、毛蕊花糖苷和异毛蕊花糖苷3种苯乙醇苷类成分含量的同时测定。微量样品粉末(0.5 mg)置于空预柱芯中并用正相硅胶填充,得到提取池后装入预柱套(Security Guard^TM)。将预柱套置于70℃柱温箱中,将一根长聚醚醚酮(PEEK)管线(1000 mm×0.13 mm)连于预柱套末端,采用0.1%(v/v)甲酸水为提取溶剂,以2.5 mL/min的速度流经PEEK管线,产生高压,实现管花肉苁蓉的在线加压溶剂微提取,通过TurboFlow cyclone色谱柱在线净化和富集。引入两个电子六通阀,将整个分析过程分为提取阶段和洗脱阶段,并在洗脱阶段将TurboFlow cyclone色谱柱中的分析物反冲至Capcell PAK C₁₈ AQ分析柱上,以0.1%(v/v)甲酸水-乙腈为流动相进行梯度洗脱,以340 nm为检测波长同时定量分析松果菊苷、毛蕊花糖苷和异毛蕊花糖苷3种苯乙醇苷类成分。结果表明,3种苯乙醇苷类在1~200 mg/L范围内线性良好,相关系数r均大于0.999,定量限分别为0.50 mg/L(松果菊苷)、0.25 mg/L(毛蕊花糖苷)和0.38 mg/L(异毛蕊花糖苷),加标回收率为83.13%~114.00%,相对标准偏差为1.89%~13.34%。该方法简便、快速、可靠,不仅节约了药材和溶剂的使用量,而且极大地简化了前处理方法,省时省力,同时显著降低了化学成分在提取过程中降解的几率,适用于管花肉苁蓉中苯乙醇苷类化合物的含量测定。     

二维液相色谱分离及鉴定滁菊中的多酚类化合物

将Lichrospher diol-5亲水柱和Cortecs C18+反相柱组合,构建了亲水/反相二维液相色谱系统(HILIC/RPLC),理论峰容量为1 117。采用表面积覆盖法定量计算该系统分离多酚类化合物的正交性指数SCG为0.56,表明二维柱系统有着良好的峰分辨率和正交性。利用该系统对滁菊样品甲醇提取液中的多酚进行分离和鉴定,在二维空间中分离得到23个物质的色谱峰,通过对比标准样品和滁菊样品的保留时间和紫外吸收光谱,鉴定出13种多酚类物质,包括芹菜素、香叶木素、金合欢素、金合欢素-7-O-葡糖苷、绿原酸、异鼠李素-3-O-葡糖苷、香叶木素-7-O-葡糖苷、金合欢素-7-O-芸香苷、圣草酚-7-O-葡糖苷、槲皮素苷、异绿原酸A、异绿原酸B、芹菜苷。首次发现滁菊中含有异鼠李素-3-O-葡糖苷、金合欢素-7-O-芸香苷、圣草酚-7-O-葡糖苷、芹菜苷等多酚类化合物。其中,异鼠李素-3-O-葡糖苷首次发现存在于菊属植物中。     

阴离子交换色谱-积分脉冲安培检测法分离测定烟草料液中的山梨醇和糖

采用阴离子交换色谱-积分脉冲安培检测法分离测定了烟草料液中山梨醇、葡萄糖、果糖、蔗糖和麦芽糖,研究了山梨醇和糖在阴离子交换色谱中的保留行为。采用优化的水和氢氧化钠二元梯度淋洗条件,CarboPac PA10阴离子交换色谱柱进行分离,积分脉冲安培检测器检测一次进样测定烟草料液样品中的山梨醇、葡萄糖、果糖、蔗糖和麦芽糖。各组分在测试条件下线性关系良好,线性范围为0.005～20 mg/L,检测限为0.2～1.0 μg/L,加标回收率为95.1%~102.4%,相对标准偏差为1.2%～1.9%。     

红枣中果糖、葡萄糖与蔗糖的高效液相色谱示差检测分析

建立了同时分析鲜红枣中果糖、葡萄糖和蔗糖的高效液相色谱方法.利用鲜红枣样品进行添加回收实验,获得方法对果糖、葡萄糖和蔗糖测定的平均回收率分别为93.5%、91.8%和89.8%,变异系数3.27%、2.34%、5.86%.结果表明:采用高效液相色谱示差分析方法定量检测鲜红枣中果糖、葡萄糖和蔗糖快速、简便.同时得出方法的检出限为:果糖5.73×10-3mg/mL,葡萄糖5.22×10-3mg/mL,蔗糖3.59×10-3mg/mL,测定结果符合食品检测要求.     

离子色谱-柱切换技术同步测定饮料中的三氯蔗糖、葡萄糖、果糖和蔗糖

建立了一种离子色谱-柱切换-安培检测技术同步测定饮料中三氯蔗糖、葡萄糖、果糖和蔗糖的方法。以CarboPac PA10阴离子交换保护柱和分析柱进行分离,用水和250 mmol/L NaOH梯度淋洗,脉冲安培检测。弱保留糖类在25 mmol/L NaOH流动相淋洗下分离检测,通过柱切换将保护柱切换至分析柱后,同时切换至250 mmol/L NaOH淋洗,三氯蔗糖仅通过较短的保护柱分离,4种糖类能够得到同步检测。4种糖类在0.01~20 mg/L范围内有良好的线性关系和较低的检出限,重复性好,样品测定的回收率分别为90.38%~102.88%（三氯蔗糖）、95.56%~102.75%（葡萄糖）、101.66%~114.33%（果糖）和105.03%~106.49%（蔗糖）。该方法可广泛应用于食品中强保留物质的测定。     

反相高效液相色谱法测定3种中成药中的葛根素

 建立了测定小儿清感灵片、步长新脑心通胶囊和感冒清热颗粒 3种中成药中葛根素含量的反相高效液相色谱方法。采用APEXODS色谱柱 ,以醋酸铵缓冲液 (10 0mmol/L ,pH 5 0 ) 甲醇 (体积比为 75∶2 5 )的混合溶液为流动相 ,检测波长为 2 5 0nm ,流速为 0 8mL/min。葛根素在 2mg/L～ 2 0mg/L时其色谱峰面积与质量浓度的线性关系良好 (r =0 9999) ;上述 3种中成药中的葛根素含量分别为 3 48mg/g ,1 0 8mg/ g及 1 5 2mg/ g(蔗糖型 ) ;其加样回收率分别为 99 0 % ,93 4%和 97 5 %。该法简便、快速、专属性强 ,可以作为多种中药制剂中葛根素含量的测定方法。     

基于电喷雾串联质谱的蓝藻寡糖脱果糖分析及系列α-1,2-葡聚寡糖的制备

为获得系列α-1,2-葡聚寡糖,首先以蓝藻寡糖六糖、八糖、九糖和十糖为原料,在0.5 mol/L的三氟乙酸(TFA)中于95℃酸解9 min以脱去还原端果糖,经低压凝胶色谱分离纯化,用电喷雾离子化-碰撞诱导解离-串联质谱(ESI-CID-MS/MS)和基质辅助激光解吸电离质谱(MALDI-MS)鉴定和序列表征,获得了除去末端果糖的α-1,2-五、七、八和九糖;然后在0.5 mol/L的TFA中于95℃对混合蓝藻寡糖六糖和八糖酸水解45 min,用Bio-Gel P2凝胶柱对混合物进行分离和纯化,并通过ESI-MS和MALDI-MS对获得的每个寡糖组份进行表征,获得了聚合度为2,3,4和6的α-1,2-葡聚寡糖.本研究为利用糖生物芯片技术进行α-1,2-葡聚寡糖的功能筛选及分析其与靶标蛋白之间相互作用的特异性提供了葡聚寡糖物质基础.     

固相萃取-高效液相色谱-二极管阵列检测器法同时测定湖水中10种蓝藻毒素

建立了固相萃取-高效液相色谱-二极管阵列检测器法测定湖水中10种蓝藻毒素(MC-RR、MC-YR、MC-Hty R、MC-LR、MC-WR、MC-LA、MC-LY、MC-LW、MC-LF和NOD)的方法。水样经固相萃取净化后,用Waters PAH C_(18)(250 mm×4.6 mm,5μm)色谱柱,以乙腈和含0.05%三氟乙酸为流动相梯度洗脱,流速为0.8 m L/min,柱温为30℃,进样量为20μL,二极管阵列检测器检测范围190~300 nm,检测波长为238 nm。根据保留时间、二极管阵列检测器全扫描光谱和色谱峰纯度分析等进行定性分析。10种蓝藻毒素在0.05~2.00 mg/L浓度范围内线性关系良好,线性系数R为0.9998~0.9999,方法检出限为0.005~0.020μg/L。3个浓度加标水平(0.1、1.0和1.8 mg/L)的回收率为85.1%~105.3%,相对标准偏差为0.8%~9.2%。本方法适用范围广、操作简单、分析速度快、灵敏度高、重现性和回收率好,采用多重定性增强了定性分析的准确性,可用于实际湖水中10种蓝藻毒素的测定。     

纤维素酶降解-离子色谱法测定魔芋中的亚硝酸盐

建立了以纤维素酶降解魔芋葡甘聚糖释放阴离子,然后采用离子色谱测定亚硝酸盐含量的方法。考察了纤维素酶降解葡甘聚糖的最佳条件,结果表明:在50 ℃、pH 5.5条件下酶解24 h,可以释放出被包埋的亚硝酸盐。NO-2的检出限为0.039 mg/L,回收率为96.7%～97.8%。运用本法对施用稀土微肥后魔芋中亚硝酸盐的含量进行测定,发现施用稀土微肥能够在一定程度上降低魔芋中亚硝酸盐的含量。     

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.     

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。     

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.     

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.     

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.     

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.     

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^-。     

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.