高效液相色谱-荧光法测定水果蔬菜中的乙萘酚

建立了柑橘、苹果、菠菜、西红柿等水果和蔬菜中乙萘酚的高效液相色谱-荧光快速检测方法。样品用乙腈提取,浓缩,乙腈-甲苯(3:1,V/V)溶解后经LC-NH2固相萃取柱净化;色谱柱:Pickering C18(250 mm×4.6 mm,5μm);流动相:乙腈-水(50:50,V/V);检测波长:λex=250 nm,λem=410 nm。乙萘酚在0.20～50.00 mg/L范围内线性关系良好(r=0.9999);在0.05,0.10,0.50 mg/kg 3个添加水平下平均回收率范围在83.3%～101.2%之间,相对标准偏差为4.3%～9.3%。     

超高效液相色谱-串联质谱法测定水果中乙撑硫脲残留

建立了水果中乙撑硫脲(Ethylenethiourea,ETU)的超高效液相色谱-串联质谱(UPLC-MS/MS)检测方法。样品经碱性乙腈(1.5%氨水乙腈)振荡提取,弗罗里硅土净化后,以乙腈-0.2%甲酸为流动相,0.4m L/min流速下梯度洗脱,经HSS T3色谱柱分离,在正离子模式下采用多反应监测(MRM)扫描测定,外标法定量。研究表明,ETU在5~200μg/L质量浓度范围内线性关系良好,相关系数均大于0.999;5,20,50μg/L 3个加标水平下,苹果、桃、葡萄、柑橘和香蕉5种基质中乙撑硫脲的加标回收率分别为93.6%~101.4%,91.2%~98.4%,84.6%~95.1%,86.8%~97.9%和79.5%~96.3%;检出限分别为0.08,0.13,0.11,0.23,0.26μg/L;定量下限分别为0.28,0.42,0.37,0.75,0.86μg/L。该方法简便、准确、经济、环保,能够满足水果中乙撑硫脲残留的快速检测要求。     

分散液液微萃取-高效液相色谱法测定水样中痕量2-萘酚

建立了分散液液微萃取-高效液相色谱法测定水样中2-萘酚的分析方法。对萃取剂、分散剂的种类和体积、萃取时间、离心时间、盐浓度等影响萃取效率的因素进行了优化。在优化后的萃取条件下(30μL氯苯作为萃取剂、0.8 mL乙腈作为分散剂、萃取时间为2 min、3000 rpm离心时间为5 min、不加盐)方法的线性范围为0.2~1000μg/L(r=0.9998),检出限为0.05μg/L(S/N=3)。2-萘酚质量浓度为100μg/L时,方法的萃取率为91.4%~105.4%,相对标准偏差为4.7%(n=11)。采用该方法对4种实际水样中的2-萘酚进行了测定,加标回收率在85.5%~104.4%之间,相对标准偏差在2.3%~12%之间(n=3)。本方法可用于环境水样中的痕量2-萘酚的检测。     

HPLC-MS/MS法检测化妆品中的萘酚

建立了多反应监测法测定化妆品中α-萘酚和β-萘酚2种禁用着色剂的高效液相色谱-二级质谱联用(HPLC-MS/MS)的分析方法.针对几类美妆用品进行了样品前处理、色谱分离条件和二级质谱条件的研究.色谱条件经优化后确定:以常用的反相键合的十八烷基为固定相,以乙腈和水的二元流动相进行梯度洗脱,以配有电喷雾离子源的二级质谱为检测器等.考察了膏霜类、油状液体类和水类不同基质化妆品中两种萘酚异构体的加标回收率,标准偏差和变异系数.在0.05~10.0mg/L的范围内,2种目标物均有良好的线性关系,检测限(S/N≥10)均为0.2ng/g.6个样品的高、中、低3个标准添加水平下,回收率为81.95%~98.30%,相对标准偏差为0.001 5%~0.078%,变异系数为0.83%~8.2%.样品中均未发现禁用着色剂萘酚的2种异构体.该方法可用于化妆品中α-萘酚和β-萘酚的检测.     

高效液相色谱-串联质谱法同时测定5种鲜水果保鲜剂的残留量

建立了高效液相色谱-串联质谱法同时测定对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、2,4-二氯苯氧乙酸(2,4-D),乙萘酚和4-苯基苯酚5种鲜水果保鲜剂残留量的分析方法。样品经乙醚提取,固相萃取活性炭柱净化后,C18色谱柱分离,以乙腈和50%甲醇水为流动相进行梯度洗脱,电喷雾负离子(ESI-)模式电离,液相色谱-质谱法(LC-MS/MS)测定。结果表明:5种保鲜剂在0.05~1.2 mg/L范围内呈现良好的线性关系,相关系数(r2)均大于0.999,5种保鲜剂的检出限为0.5~20μg/kg。方法的加标回收率为81.0%~104.5%,相对标准偏差(RSD)为1.3%~6.8%。该方法简便快捷、灵敏度及准确性高,可满足鲜水果防腐保鲜剂残留量检测的要求。     

固相萃取-高效液相色谱法测定偶氮染料橙黄G的降解产物1-胺基-2-萘酚-6,8-二磺酸

提出了固相萃取-高效液相色谱法测定偶氮染料橙黄G的Fenton反应降解溶液中1-胺基-2-萘酚-6,8-二磺酸。用OnGuardⅡH固相萃取小柱去除降解液中的Fe2+,C18柱为分离柱,以乙腈-10mmol·L-1乙酸铵(20+80)溶液为流动相洗脱,检测波长为254nm。1-胺基-2-萘酚-6,8-二磺酸的线性范围为0.05~5.0mg·L-1,检出限(3S/N)为0.15mg·L-1。加标回收率在92.1%~99.2%之间,日内及日间相对标准偏差分别在2.8%~3.4%,4.1%~7.7%之间。     

高效液相色谱-串联质谱法同时测定染发剂中的1-萘酚和2-萘酚

提出了同时测定染发剂中1-萘酚和2-萘酚的高效液相色谱-串联质谱分析方法。染发剂样品经甲醇-水(1+1)混合液萃取,ProElut PLS固相萃取小柱净化,净化液吹氮蒸干后残渣用甲醇溶解并定容为1mL。此溶液经Agilent ZORBAX SB-C18色谱柱(2.1mm×150mm,3.5μm)分离,用不同体积比混合的乙腈和水梯度洗脱,采用电喷雾负离子模式多反应监测。1-萘酚和2-萘酚的线性范围均为0.05~10.0mg·L-1,检出限(3S/N)均为0.05mg·kg-1,测定下限(10S/N)均为0.2mg·kg-1。方法应用于测定实际样品中上述两化合物。以空白样品作基体加入混合标准溶液做回收试验,测得回收率在82.5%~102%之间,测定值的相对标准偏差(n=10)在6.3%~11%之间。     

固相萃取-高效液相色谱法同时测定大豆和大米中的磺酰脲类和二苯醚类除草剂残留

建立了大豆和大米中磺酰脲类和二苯醚类除草剂多残留同时检测的高效液相色谱分析方法。样品经乙腈提取,正己烷液-液分配,C18固相萃取小柱净化后,采用高效液相色谱方法分离,以乙腈-三乙胺盐酸溶液作流动相,梯度洗脱,紫外检测器检测。对样品前处理和色谱分析条件进行了优化,8种除草剂(甲磺隆、氯磺隆、苄嘧磺隆、吡嘧磺隆、三氟羧草醚、精恶唑禾草灵、乙氧氟草醚、乙羧氟草醚)在0.05~2.0 mg/L范围内线性关系良好。方法的定量限(S/N=10)为0.01~0.02 mg/kg,能达到国家有关上述除草剂残留限量的要求。大豆和大米样品的平均加标回收率分别为91.6%~116.1%和76.6%~110.8%,相对标准偏差(RSD)为1.0%~12.2%。所建立的方法在30 min内可完成一次检测,具有简便快速、灵敏可靠的特点,适用于大豆和大米中除草剂多残留的测定。     

乳及乳制品中黄曲霉毒素B_1、M_1测定方法改进

建立了一种检测乳及乳制品中黄曲霉毒素B1、M1的高效液相色谱-荧光检测(HPLC-FD)方法。样品经60%乙腈溶液提取,自制固相萃取柱净化,流出液经正己烷、三氟乙酸衍生后荧光检测器检测。考察了填料、柱容量、取样量、提取溶液和流速等对检测的影响,优化了实验条件。结果表明,黄曲霉毒素B1、M1的检测线性范围为0.40~100μg/L,线性系数为0.9991~0.9998,方法检出限为0.050μg/kg。对样品进行0.40、1.0和15μg/L 3种浓度水平的加标回收实验,回收率为53%~105%,相对标准偏差为2.6%~5.1%。该方法操作简单、灵敏度高、准确度好,可用于乳及乳制品中黄曲霉毒素B1、M1的测定。     

QuEChERS-超高效液相色谱-串联质谱法测定鸡蛋中125种兽药残留

采用冷冻脂质过滤,结合分散固相萃取净化的QuEChERS方法,建立了超高效液相色谱-串联质谱法测定鸡蛋中125种兽药残留的检测方法。样品中的11类兽药（硝基咪唑类、苯并咪唑类、磺胺类、喹诺酮类、四环素类、大环内酯类、雄激素类、孕激素类、糖皮质醇类、雌激素类、氯霉素类）用70%（v/v）乙腈-水溶液（含0.1 mol/L EDTA）提取后,提取液在-20℃冷冻处理2 h,再经分散固相萃取法净化,净化液经稀释后,以超高效液相色谱-串联质谱法测定,外标法定量。结果显示125种兽药的线性相关系数R²≥0.99,定量限范围为2.0~60 μg/kg,回收率在60.4%~119.3%之间,相对标准偏差在0.3%~16.1%之间。该方法前处理简单、准确、成本较低,适用于鸡蛋中兽药残留的高通量快速检测分析。     

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。     

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.

     

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.     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

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.     

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^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。