超高效液相色谱-串联质谱法测定具色塑料餐具中33种初级芳香胺的残留量和迁移量

测定33种初级芳香胺(PAAs)残留量的具色塑料餐具样品前处理方法为:1能溶于二氯甲烷的塑料餐具样品用二氯甲烷超声提取;2对不溶于二氯甲烷的样品,用二氯甲烷作溶剂进行超声溶胀提取。在色谱分离中,用BEH Phenyl柱为固定相,以不同体积比的水和甲醇(含φ0.07%甲酸)的混合液作为流动相进行梯度洗脱。质谱分析时采用电喷雾正离子源和多反应监测模式,同位素内标法定量。33种PAAs残留量和迁移量的检出限(3S/N)依次在6~10μg·kg-1和0.03~0.5μg·kg-1之间;两者的回收率分别在60.1%~119%和72.5%~115%之间,测定值的相对标准偏差(n=6)依次为2.3%~15%和2.8%~14%。     

超高效液相色谱-串联质谱法快速测定纸质包装材料中多类防腐剂

建立了同时测定纸质包装材料中酸类、酯类和酮类防腐剂的超高效液相色谱-串联质谱法。对样品萃取条件、色谱分离条件和质谱条件进行了优化。样品以10 m L甲醇-乙酸铵/乙酸缓冲液(75∶25,V∶V)为萃取溶剂振荡萃取20 min。提取液以甲醇和乙酸铵/乙酸缓冲液为流动相,梯度洗脱,以电喷雾离子源正、负离子同时多反应监测(MRM)模式进行监测,分析检测时间为10 min。方法的定量限为0.14~2.80 mg/kg,RSD为4.3%~9.8%,空白样品加标回收率为85.1%~108.1%。考察了质谱检测的基质效应,发现基质效应不明显。该方法满足纸质包装材料中多种类防腐剂同时快速测试的要求。     

微波辅助萃取/气相色谱-质谱法同时测定纸质食品接触材料中18种多环芳烃

建立了同时测定纸质食品接触材料中18种禁用多环芳烃的气相色谱-质谱/选择离子监测方法。以二氯甲烷-正己烷(1∶1)为提取溶剂,在90℃下微波辅助萃取纸质食品接触材料中的多环芳烃,提取液经二甲亚砜萃取、环己烷反萃取、硅胶固相萃取柱净化后,进行气相色谱-质谱/选择离子监测分析,外标法定量。各组分的检出限为0.1~1.0μg/kg,相关系数均大于0.997,加标回收率为56.3%~95.4%,相对标准偏差均小于7%。该方法简便快捷、灵敏度高、定性定量准确,适用于纸质食品接触材料中多环芳烃的同时测定。     

气相色谱-三重四极杆串联质谱法同时测定烟草中8种生物碱

建立了气相色谱-三重四极杆串联质谱(GC-MS/MS)分析烟草中8种主要生物碱的方法。样品经10%NaOH溶液浸提,二氯甲烷超声萃取后,采用GC-MS/MS多反应监测(MRM)模式测定,内标法定量。8种生物碱的回收率为93.2%~99.0%,相对标准偏差为2.8%~6.7%。该方法简单快速、灵敏准确,适用于烟草样品中生物碱的快速测定。     

超声萃取/气相色谱-质谱联用法测定汽车涂料中的11种芳香胺

建立了气相色谱-质谱联用法(GC-MS)测定汽车涂料中的11种芳香胺的方法,以乙腈为溶剂,采用超声萃取前处理,高速离心,过滤取清液后,通过Elite-5MS色谱柱分离,质谱测定,选择离子监测模式定量。结果表明:11种芳香胺在0.6~30 mg/L范围内线性关系良好,相关系数大于0.997,定量限为0.25~2.36 mg/kg,检出限为0.08~0.73 mg/kg,加标回收率和精密度良好,加标回收率在86.2%~109.8%之间,精密度6.9%。方法能够满足汽车涂料中11种芳香胺的分析要求。     

纸质包装材料中甲醛、乙醛向食品模拟物改性聚苯醚的迁移行为

为了解纸质包装材料中甲醛、乙醛向食品模拟物改性聚苯醚( Tenax)中的迁移行为,建立了一步提取衍生化、超高效液相色谱测定纸质包装材料和Tenax中的甲醛和乙醛的方法。本方法在甲醛和乙醛的测定范围内,线性相关系数R2>0.9999,甲醛检出限为0.03 mg/m2,乙醛检出限为0.04 mg/m2,测定纸样和Tenax的加标回收率为90.1%~108.6%。采用本方法研究不同温度和时间下两种纸质包装材料中甲醛、乙醛向Tenax中的迁移规律。研究表明,甲醛、乙醛迁移行为随时间变化趋势大致相同,均呈现迁移率随迁移时间延长先迅速增大,后又减小达到一个常数;甲醛和乙醛迁移率受温度的影响不同,达到平衡后,甲醛在30℃下迁移率最高,乙醛在70℃和50℃下迁移率高;甲醛和乙醛向Tenax中的迁移率差异较大,达到平衡后,乙醛的迁移率远高于甲醛。     

气相色谱法检测纸质包装材料中9种有害物质

建立了快速测定纸质包装材料中甲苯、邻二甲苯、间二甲苯、对二甲苯、萘、十四烷、二苯甲酮、硬脂酸甲酯、邻苯二甲酸二丁酯9种有害物质的气相色谱法。纸质包装材料样品进行溶剂萃取,用气相色谱-氢火焰离子化检测器法同时测定样品的9种有害物质。对萃取剂、萃取温度和时间以及色谱条件进行了考察,方法的线性范围为0~100μg/mL,检测限为0.01~0.05μg/mL,回收率为91.7%~111.4%,相对标准偏差为3.59%~7.76%。该方法操作简单,定量准确可靠。     

固相萃取/气相色谱-质谱法对接触食品的塑料制品中24种芳香族伯胺迁移量的同时测定

建立了固相萃取/气相色谱-质谱同时测定接触食品的塑料材料和制品中24种受限的芳香族伯胺特定迁移量的分析方法.样品中24种目标物用蒸馏水浸出后,经固相萃取小柱富集净化,再用叔丁基甲醚洗脱,洗脱液氮吹浓缩定容后用气相色谱-质谱法测定.不同的芳香族伯胺,方法的检出限略有差异,为0.01 ～1 μg/kg;各种芳香族伯胺的含量在10 μg/kg时获得的相对标准偏差(n=6)为3.8% ～14.7%.方法完全满足欧盟指令2007/19/EC对接触食品的塑料制品中芳香族伯胺特定迁移量的限量要求.利用该法检测了43批近期经宁波口岸出口的接触食品的塑料制品,仅有2批次分别检出了2-氯苯胺和二甲基苯胺.     

气相色谱-质谱联用法测定纸吸管中二甘醇二苯甲酸酯的迁移量

建立气相色谱-质谱联用法测定纸吸管在水、4%乙酸溶液、10%乙醇溶液和50%乙醇溶液四种食品模拟物中二甘醇二苯甲酸酯（DEDB）迁移量的方法，并探讨了DEDB向模拟物中迁移的规律。以乙酸乙酯作萃取剂，萃取食品模拟物中的DEDB，萃取液经HP-5MS色谱柱（30 m×0.25 mm,0.25μm）分离，采用气相色谱-质谱联用法检测，内标法定量。在质量浓度为0.2～10.0 mg/L范围内，DEDB与内标物的质量浓度比和与苯甲酸苄酯监测离子丰度比线性关系良好，相关系数r为0.999 0，方法检出限为0.05 mg/L，定量限为0.2 mg/L。样品加标回收率为91.2%～103.6%，相对标准偏差为3.1%～8.5%(n=6)。在相同的温度和时间下，DEDB迁移量从小到大的顺序依次为：水、4%乙酸溶液、10%乙醇溶液、50%乙醇溶液。该方法简便、快速，适用于纸吸管中DEDB迁移量的测定。     

Tenax采样管富集气相色谱-质谱法测定空气中的痕量酚类化合物

建立了Tenax采样管富集气相色谱-质谱测定空气中痕量酚类化合物的方法。用Tenax采样管吸附环境空气中的痕量酚类化合物,用甲醇淋洗解吸酚类化合物,洗脱液加入萘-D8作为内标,利用气相色谱-选择离子监测质谱(GC-MS/SIM)进行检测,内标法定量。该方法定性、定量准确,线性响应良好,回归曲线的线性相关系数均大于0.999,平均回收率为92.4%～102%,测定干扰小,检测灵敏度高,按采样10 L计算,空气中最低检测浓度可达0.001 mg/m3。用于实际样品测定,完全能满足环境空气中痕量酚类化合物监测的要求。     

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。     

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。     

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.     

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.     

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.     

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。     

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.