扁桃酸对映体光学纯度的柱前衍生化HPLC测定

建立了一种用高效液相色谱(HPLC)测定扁桃酸光学纯度的新方法。用苯胺将扁桃酸衍生化,产生相应的对映体衍生物,正己烷为流动相,乙醇和异丙醇作极性调节,用DNB-Leucine色谱柱进行分离。考察了流动相组成和柱温对其分离的影响,确定分析条件为:流动相为V(正己烷)∶V(乙醇)=85∶15,温度20℃,流速1.5 mL/min。在此条件下拆分扁桃酸衍生物对映体,达到基线分离,分析时间在7 min以内,分离因子达到1.62。与旋光仪方法的测定结果一致,两种方法测定的光学纯度偏差不超过1.96%。该方法可以准确、方便地测定扁桃酸的光学纯度。     

高效液相色谱-二极管阵列检测法测定护发产品中肌酸

建立了护发产品中肌酸的高效液相色谱(HPLC)测定方法.样品经流动相溶解并提取,采用偏磷酸溶液为流动相,流速为1.0 mL/min,以C8色谱柱(250 mm×4.6 mm 5μm)进行分离,二极管阵列检测器进行检测,检测波长为210 nm.在上述条件下,目标物质与样品的杂质获得有效分离,在2～100 mg/L范围内,质量浓度与峰面积呈良好的线性关系.对护发产品进行添加回收,回收率为92.5%～101.6%,RSD为2.0%～3.7%.已用于护发产品中肌酸含量的分析.     

高效液相色谱对液态奶中三聚氰胺的快速测定

建立了有机溶剂提取和离子对色谱相结合的三聚氰胺快速检测方法.样品中加入有机溶剂振荡提取,取上清液过滤进行高效液相色谱(HPLC)分析.对丙酮、乙腈、乙醇和异丙醇的提取物分别在甲醇-离子对试剂流动相体系和乙腈-离子对试剂流动相体系中进行测定和比较.结果显示,选择合适的流动相,使用丙酮、乙醇或异丙醇为提取剂可以获得较好的提取效果.在甲醇-离子对试剂流动相体系中,三聚氰胺的质量浓度在1.0 ～100.0 mg/L范围内与色谱峰面积呈良好的线性关系(r=0.999 98),检出限为0.1 mg/kg,采用丙酮为提取剂,加标回收率为97% ～103%,相对标准偏差(RSD)小于5%.     

高效液相色谱法测定鸡肉中己烯雌酚

采用高效液相色谱法(HPLC)测定鸡肉中己烯雌酚残留量,将碎鸡肉用甲醇超声提取,合并提取液浓缩近干,用甲醇溶解残渣,所得溶液用于 HPLC 测定.Symmetry C,18用作色谱柱,甲醇与0.012 8 mol·L-1 磷酸二氢钠溶液以63比37(体积比)混合后作为流动相,流速为 1.0 mL·min-1.在230 nm波长处,用二极管阵列检测器检测.对鸡肉样品作了分析,测定结果的相对标准偏差(n=5)均小于 10%,回收试验给出回收率在 87.5%～92.3%之间.测得方法的检出限(S/N=3)为 20 μg·kg-1.     

1,3,5,7-四乙酰基-1,3,5,7-四氮杂环辛烷合成反应中间体的制备分离

1,3,5,7-四乙酰基-1,3,5,7-四氮杂环辛烷(TAT)是高能炸药奥克托今(HMX)重要的合成反应前体之一,1,5-二乙酰基-1,3,5,7-四氮杂环辛烷(DAPT)醋酐酰解法和乙腈甲醛小分子缩合法均能制备得到TAT.采用半制备高效液相色谱制备分离了上述两种制备方法反应原液中的六种中间体,分别是1-乙酰氧甲基-3,5,7-三乙酰基-1,3,5,7-四氮杂环辛烷、1,3,5-三乙酰基-1,3,5,7-四氮杂环辛烷、1-乙酰氧甲基-3,5,7-三乙酰基-1,3,5,7-四氮杂环辛烷、N,N’-亚甲基二乙酰胺、三乙酰胺二亚甲基三胺和四乙酰胺三亚甲基四胺,为反应机理研究提供了有力的证据.DAPT醋酐酰解法反应原液样品的最佳制备色谱条件为:正相硅胶柱(20 mm×250 mm,10～20μm),流动相:V(乙腈)∶V(甲醇)=95∶5,流速为10 mL·min-1,检测波长为215 nm,进样量为1 mL,样品浓度30 mg/mL.乙腈甲醛小分子缩合法反应原液样品的最佳制备色谱条件为:正相硅胶柱(20 mm×250 mm,10～20μm),流动相:V(乙腈)∶V(水)=90∶10,流速为10 mL·min-1,检测波长为215 nm,进样量为1 mL,样品浓度30 mg/mL.制备得到的中间体经HPLC分析知纯度均在97%以上,可直接作为结构鉴定的标准样品.     

UPLC-MS/MS法测定7类化妆品中4-氨基联苯

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)检测化妆品中4-氨基联苯的方法。化妆品样品经溶剂超声提取、净化(液液萃取或固相萃取),氮气吹至近干并定容后,通过高效液相色谱-串联四极杆质谱仪检测。分离柱为Waters Acquity BEH C18柱(1.7μm,2.1 mm×100 mm);流动相为0.3%甲酸水溶液-乙腈;流速0.5 mL·min-1。7种不同基质样品中4-氨基联苯的检测限均小于1.0ng·g-1。7种不同基质样品中4-氨基联苯的回收率为85.3%～111.2%,相对标准偏差(RSD)为0.93%～4.11%(n=3),在2.5ng·mL-1～250ng·mL-1浓度范围内呈良好的线性关系,线性回归系数r2均大于0.999。     

藏药诃子质量标志物诃子酸的分离分析及标准化研究

依据GB/T 15000—2008《标准样品工作导则》的要求,研制诃子酸国家标准样品.以诃子的干燥成熟果实为原料,采用大孔吸附树脂、制备型高效液相色谱技术对标准样品进行制备,经过纯度分析、结构鉴定、均匀性检验、稳定性检验,最后进行联合定值.基于高效液相色谱(HPLC)技术,采用不同检测波长进行纯度测试,样品纯度均大于98%.基于液相-质谱(LC-MS)进行纯度分析,未发现明显杂质峰.通过紫外光谱(UV)、红外光谱(IR)、质谱(MS)、核磁共振(NMR)等技术确定其结构为诃子酸.样品均匀性良好,4℃条件下24个月内稳定性良好.定值结果确定诃子酸纯度为98.08%,在95%置信区间范围内的相对扩展不确定度为0.50%.研制出的诃子酸(GSB 11-3725-2020)国家标准样品可用于含量测定、检测方法评定、相关产品的检测与质量控制.     

固相萃取/高效液相色谱荧光法测定水产品中苯并芘

采用Florisil固相萃取柱纯化样品,建立了高效液相色谱(HPLC)荧光法测定水产品中苯并(a)芘的方法.样品以正己烷为提取剂,净化、蒸发浓缩后用流动相溶解.荧光检测器激发波长297 nm,发射波长405 nm.流动相为V(乙腈):V(水)=75:25,流速1.0 mL/min,外标法定量.苯并(a)芘在0～200 ng/mL浓度范围内线性关系良好,相关系数r=0.99990;在5个空白样品中添加0.5μg/kg浓度水平的标准品,回收率在81.9%～89.5%之间,相对标准偏差为4.1%(n=5);日内、日间精密度分别为0.7%(n=5)、2.4%(n=3);最低检测限为90 ng/kg.     

液相色谱-串联质谱法测定10种食品中四溴菊酯残留

建立了测定蔬菜、水果、茶叶、大豆等10种食品中四溴菊酯残留的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。样品以乙酸乙酯(蔬菜、水果、茶叶样品)或乙腈(大豆样品)为提取剂,上层有机相经浓缩、固相萃取小柱净化,流动相定容后,采用HPLC在Agilent ZORBAX Eclipse XDB C18色谱柱上,以甲醇和缓冲盐溶液(0.1%甲酸-10 mmol/L乙酸铵)为流动相进行梯度洗脱分离,以串联质谱在多反应监测(MRM)模式下测定,基质外标法定量。结果表明,四溴菊酯的质量浓度在20～1 000μg/L范围内线性关系良好,相关系数为0.999 8;在0.01、0.02、0.1 mg/kg(粮谷类、茶叶、大豆样品)和0.005、0.01、0.05mg/kg(果蔬类样品)加标水平下的回收率为75%～92%,相对标准偏差(RSDs)为4.0%～12.6%(n=6),定量下限(S/N≥10)为0.01 mg/kg(粮谷类、茶叶、大豆样品)和0.005 mg/kg(果蔬类样品)。该方法不受溴氰菊酯干扰,可直接测定四溴菊酯,克服了以往方法只能测定四溴菊酯和溴氰菊酯总量的不足。     

高效液相色谱法测定电子电气产品中多溴联苯和多溴联苯醚

提出了高效液相色谱法测定电子电气产品中多溴联苯和多溴联苯醚含量的方法。普通塑料样品采用正己烷-丙酮(1+1)混合溶液作为提取溶剂进行微波萃取,含金属的塑料样品采用乙酸乙酯作为提取溶剂进行超声波萃取,提取液采用NUCLEODUR Sphinx RP C18色谱柱为分离柱分离,以不同体积比混合的水和乙腈为流动相进行梯度洗脱,检测波长为226nm。多溴联苯和多溴联苯醚的质量浓度在0.2～50mg.L-1范围内与峰面积呈线性关系,测定下限(10S/N)在2.3～5.0mg.kg-1之间。     

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。     

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.     

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.     

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.     

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。     

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.