离子液体固定相离子色谱法测定淀粉中的顺反式丁烯二酸

采用新型聚合离子液体嫁接硅胶多模式色谱固定相(Sil-pC11C1Im柱,4.6 mm×150 mm),建立了淀粉中顺反式丁烯二酸的新型离子色谱测定方法。实验通过考察流动相的pH值和无机盐浓度对分离检测顺、反丁烯二酸的影响,得到优化的色谱条件:流动相为甲醇-10 mmol/L磷酸二氢钠(体积比为5∶95,pH7.0),流速为1.0 mL/min,检测波长为215 nm,进样量为15μL。在优化条件下,顺反式丁烯二酸的线性范围为0.1~2.0 mg/L,回收率为93.0%~99.6%,相对标准偏差(RSD,n=5)为1.1%~7.6%,检出限(S/N=3)为0.02 mg/L,定量下限(S/N=10)为0.66 mg/kg。该方法样品前处理简单、快速,定性定量检测效果良好。     

酮洛芬与蛋白结合作用的高效液相色谱-迎头分析法研究及其与高效毛细管电泳-迎头分析法的比较

采用高效液相色谱-迎头分析法(HPLC-FA),以67 mmol/L (pH 7.4, I=0.17 mol/L) 的等渗磷酸盐缓冲液为流动相,Pinkerton GFF　Ⅱ-S5-80内表面反相柱(150 mm×4.6 mm i.d., 5 μm)为固定相,254 nm下检测,研究了酮洛芬与人血清白蛋白(HSA)的结合作用,通过非线性回归参数估算求得酮洛芬与HSA的结合参数。与高效毛细管电泳-迎头分析法(HPCE-FA)相比,HPLC-FA法具有高灵敏度的优势,但进样量较大,分析时间较长。HPLC-F     

血浆辅酶Q10的高效液相色谱快速测定

建立了一种简单快速测定血浆辅酶Q10(CoQ10)的反相高效液相色谱方法.血浆经正丙醇萃取,上层清液直接进样分析.色谱柱为Hypersil ODS2 5μm,150 mm ×4.6 mm i.d,以异丙醇-甲醇(体积比19)作流动相,275 nm作检测波长,外标法定量.在0.05～20 mg/L范围内,峰高与质量浓度呈良好的线性关系(r=0.999 8),血浆中辅酶Q10的检出限为0.03 mg/L(S/N=3).该方法简单、快速、精密度高(RSD＜5%),适宜于血浆辅酶Q10含量的检测.     

高效液相色谱法同时测定人血清中5-氟尿嘧啶及其代谢物5-脱氧尿苷

5-氟尿嘧啶(5-fluorouracil,5-FU)是治疗消化道恶性肿瘤的首选药,为探讨其最佳给药方案,本文利用高效液相色谱(HPLC)建立了同时测定人血清中5-FU及其活性代谢物5-脱氧尿苷(5-fluoro-2′-     

高效液相色谱-质谱法对饲料及食品添加剂中三聚氰胺的测定

建立了饲料中三聚氰胺的高效液相色谱-质谱测定方法.色谱条件:Kromasil C18柱(4.6 mm×250mm,5 μm),流动相:乙腈-0.1%(体积分数)甲酸(体积比5:95),流速0.4 mL/min.采用正离子模式的电喷雾质谱检测,以一级质谱得到的准分子离子m/z 127作为母离子,进行碰撞诱导解离(CID)二级质谱(MS2)分析,选择母离子和MS2的碎片离子m/z 85、109定性确证,提取m/z 85、109、127三个离子质量色谱峰面积定量.实验优化了质谱条件.线性范围为0.01～0.5 mg/L,检出限0.01 mg/L(S/N=3),回收率为80%～99%.     

高效液相色谱-内标法测定碘硝酚原料及其注射液中碘硝酚的含量

建立了碘硝酚的高效液相色谱(HPLC)-内标法检测方法。用甲醇将样品配制成测试浓度后过滤,经依利特Sino Chrom C_(18)(4.6 mm×200 mm,5μm)色谱分析柱进行色谱分离,流动相为0.02 mol/L磷酸二氢钾溶液(pH 2.6)-甲醇(30∶70),流速为1 mL/min,紫外检测波长为235 nm,柱温为30℃,内标物为硝氯酚,进样量为20μL。结果表明,碘硝酚的质量浓度在20~120 mg/L范围内呈线性关系,相关系数(r)为0.999 6;在3个不同浓度(64、80、96 mg/L)加标水平下,平均回收率为90.4%~98.2%,相对标准偏差(RSD)为0.18%~0.72%;检出限(LOD,S/N=3)为0.15 mg/L,定量下限(LOQ,S/N=10)为1.5 mg/L。该方法的精密度、稳定性以及重复性良好,且操作简便,结果准确,可用于碘硝酚原料药及注射液的含量测定。     

硫辛酸片含量与降解物的高效液相色谱测定研究

建立了硫辛酸片中硫辛酸及其降解物快速测定的高效液相色谱方法。采用Waters XBridge色谱柱(5μm,150 mm×4.6 mm),流动相为0.05 mol/L磷酸二氢钾溶液(磷酸调至pH 2.5)-乙腈-甲醇(50∶45∶5),流速为1.0 mL/min,进样量为20μL,二极管阵列检测器,检测波长为220 nm,全波长扫描范围为200～400 nm,柱温为室温。结果表明,在上述色谱条件下,硫辛酸浓度在0.4～20.0 mg/L范围内线性关系良好(r=0.999 9);其检出限为0.2 mg/L;定量下限为0.6 mg/L;精密度RSD(n=12)为3.4%;加标回收率为100.9%,RSD为2.0%。该法简便、快速、准确、选择性好、灵敏度高,可用于硫辛酸片含量与降解物的测定。     

HPLC法测定高原鼠兔血清中的硝酸盐

建立了高原鼠兔血清中硝酸盐(NO3-)含量测定的HPLC方法,这是除离子色谱法之外,为研究动物血清内NO3-含量提供的另一种方法。采用Sym-metryRRC18(5μm,4.0mm×250mm)色谱柱;V(10mmol/L的四乙基硫酸氢铵溶液,PH=8.4):V(乙腈)=90∶10为流动相;检测波长210 nm;流速0.8mL/min。NO3-在0.3125~10mg/L的范围内有很好的线性关系(R=0.9998)。结果表明,采集于青藏高原地区昆仑山和果洛区域的高原鼠兔血清内NO3-总含量在72.0mg/L~192mg/L。     

超高效液相色谱法同时测定烟用香精料液中的糠醛、5-羟甲基糠醛与5-甲基糠醛

建立了同时测定烟用香精料液中糠醛、5-羟甲基糠醛和5-甲基糠醛的超高效液相色谱(UPLC)方法。样品经流动相稀释、振荡、过滤后,采用C18(2.1 mm i.d.×100 mm,1.7μm)柱,以乙腈-水(10∶90)为流动相,在流速0.3 m L/min条件下等度洗脱分离,以二极管阵列检测器在波长280 nm下检测,外标法定量。该方法5 min内即可实现3种目标物的分离,5-羟甲基糠醛、糠醛和5-甲基糠醛的线性范围分别为0.004 2~40.00 mg/kg,0.004 6~30.00 mg/kg,0.006 9~30.00 mg/kg;相关系数(r2)分别为0.999 2,0.999 9和0.999 8;检出限(S/N=3)分别为1.24,1.37,2.06μg/kg;相对标准偏差(RSD,n=11)为0.1%~0.4%;加标水平为0.005 0~10.18 mg/kg时,3种化合物的回收率为91.7%~106.0%。该方法操作简便、分析快速、结果准确,适用于烟用香精料液中5-羟甲基糠醛、糠醛和5-甲基糠醛的检测。     

高效液相色谱法测定中药材补骨脂中补骨脂素和异补骨脂素的含量

 建立了测定中药材补骨脂中补骨脂素和异补骨脂素含量的高效液相色谱法。采用的色谱条件为:Hypersil ODS色谱柱(150 mm×4.6 mm i.d., 5 μm),以乙腈-水(体积比为30∶70)为流动相,检测波长为245 nm。在此条件下,补骨脂素、异补骨脂素和内标物联苯苄唑获得了较好的分离。补骨脂素和异补骨脂素质量浓度分别为0.50～10.0 mg/L 时,组分与内标的峰面积比值与质量浓度之间的线性关系良好(r=1.000),最低检测限为10 μg/L (S/N=3) 。所建立的方法用于不同     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

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.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

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.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

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。