同位素稀释-固相萃取-LC/MS/MS法测定婴幼儿配方食品中双酚类化合物

建立了同位素稀释-固相萃取-高效液相色谱-串联质谱法同时测定婴幼儿配方食品中14种双酚类化合物的方法。婴幼儿配方乳粉、婴幼儿配方谷粉和婴幼儿辅食果泥等试样经乙腈提取,ProElut PLS 固相萃取小柱(500 mg/6 mL)净化,14种双酚类化合物经Waters Atlantis T3色谱柱(150 mm ×2.1 mm,3.0μm)分离后,正负离子同时扫描模式下多反应监测( MRM),基质匹配BPA-d16、TBBPA-d10和BPS-c13同位素内标法定量。结果表明,在线性范围内,14种双酚类化合物线性相关系数( r)均大于0.999,回收率为83.0%~107.1%(n=6),相对标准偏差(RSD)为5.1%~9.8%(n=6),方法的定量限(LOQ)为1.0~2.0μg/kg,检出限(LOD)为0.3~0.7μg/kg。方法操作简单、高效、重现性好,满足现行法规要求的同时,实现了婴幼儿食品中双酚类化合物的定性定量检测。     

超高效液相色谱-串联质谱法测定鸡肉中头孢拉定残留

建立测定鸡肉中头孢拉定残留的超高效液相色谱-串联质谱分析方法。鸡肉样品经80%乙腈水溶液提取,PRiME HLB柱固相萃取净化,0.2%甲酸水溶液稀释,采用Waters ACQUITY UPLC HSS T3色谱柱(100 mm×2.1 mm,1.8μm)分离,以0.1%甲酸-0.1%甲酸乙腈为流动相,梯度洗脱,基质加标外标法定量。实验结果表明,头孢拉定在0.5～50.0 ng/mL浓度范围内呈良好的线性关系(R~2=0.9998),定量限为1μg/kg。向空白鸡肉中添加头孢拉定含量为1.00μg/kg、2.00μg/kg、10.0μg/kg时,回收率在77.3%～106.8%之间,相对标准偏差在3.2%～10.5%之间。本方法操作简便、快捷,实验结果准确、稳定,可满足鸡肉中头孢拉定残留量的检测。     

加速溶剂萃取/超高效液相色谱-串联质谱法测定沉积物中三苯甲烷类杀菌剂

采用超高效液相色谱-三重四极杆质谱(UPLC-MS/MS),结合加速溶剂萃取(ASE)前处理技术,建立了同时测定沉积物中3种三苯甲烷类残留(孔雀石绿、结晶紫、亮绿)的方法。干燥研磨后的底泥样品用中性氧化铝混合分散,以乙腈-Mc Ilvaine缓冲溶液(体积比10∶2)为萃取液,经ASE萃取富集后进入液相色谱-串联质谱分析,内标法定量。结果表明:3种三苯甲烷类化合物的峰形对称并完全分离,在0.5~50.0μg/L范围内线性良好(r0.998);在1 500 psi压力及60℃萃取温度下,目标物的回收率为65.8%~112%,相对标准偏差(n=6)为5.1%~14.4%,方法检出限为0.006~0.007μg/kg,定量下限为0.024~0.028μg/kg。该方法已用于滆湖沉积物中3种目标化合物的检测,为我国环境监管提供了技术支撑和数据支持。     

加速溶剂萃取-高效液相色谱-串联质谱法同时检测鱼肉中喹诺酮、磺胺与大环内酯类抗生素

建立了加速溶剂萃取(ASE)-高效液相色谱-串联质谱联用法同时检测鱼肉中22种抗生素药物残留的分析方法。样品经ASE提取,HLB固相萃取柱净化后进入高效液相色谱-串联质谱仪分析。对ASE的萃取条件进行优化,并采用XTerraMSC18柱对药物进行分离,以甲醇-乙腈(体积比1∶1)为色谱流动相A,以0.3%(体积分数)甲酸水溶液(含0.1%甲酸铵,pH=2.9)为流动相B。22种喹诺酮、磺胺和大环内酯类抗生素药物在加标水平为20、100μg/L时的回收率分别为72%～120%与66%～114%,相对标准偏差(RSD,n=5)分别为1.9%～16%与0.7%～10%,方法的检出限为0.02～0.6μg/kg。结果显示所建立的方法精密度好,准确度高,可满足同时对鱼肉样品中多种喹诺酮、磺胺和大环内酯类抗生素残留进行定性及定量分析的要求。     

高效液相色谱-三重四极杆串联质谱法同时测定化妆品中24种香豆素类化合物

建立了高效液相色谱-三重四级杆串联质谱法同时测定化妆品中24种香豆素类化合物含量。水基、乳液、膏霜类样品和唇膏、粉饼等固态类样品分别采用甲醇、甲醇-四氢呋喃(1∶1)混合溶液超声提取后,经Agilent Poroshell120 SB-C₁₈色谱柱(100 mm×4.6mm,2.7μm)分离,以甲醇-5 mmol/mL甲酸铵(含0.1%甲酸)溶液作为流动相进行梯度洗脱,流量为0.5 mL/min,多反应监测模式检测。24种香豆素类化合物在各自质量浓度范围内与色谱峰面积线性关系良好,相关系数均不小于0.999 5,检出限为0.002～0.8μg/kg,定量限为0.004～3μg/kg。在低、中、高三个浓度加标水平下,样品平均加标回收率为84.8%～112.9%,测定结果的相对标准偏差为1.2%～9.8%(n=6)。该方法操作简便、灵敏度高、准确性好,可用于化妆品中香豆素类化合物的定性筛查和定量测定。     

超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法测定焙烤食品及其原料中11种真菌毒素

建立了超高效液相色谱-四极杆/静电场轨道阱高分辨质谱(UPLC-HRMS)测定焙烤食品及其原料中11种真菌毒素的检测分析方法。样品经20 mL含1%(体积分数)甲酸的乙腈-水(9∶1,v/v)溶液提取,经2.0 g无水硫酸、0.5 g氯化钠和300 mg C18盐析、净化后进行检测。采用CORTECS C18色谱柱(100 mm×2.1 mm,1.6μm),以含0.1%(体积分数)甲酸的2 mmol/L乙酸铵溶液和含0.1%(体积分数)甲酸的2 mmol/L乙酸铵甲醇溶液为流动相进行梯度洗脱。结果显示,11种真菌毒素在各自的质量浓度范围内线性关系良好(相关系数r2≥0.996 0),方法的定量限为0.15~20.00μg/kg,样品加标回收率为64.38%~122.61%,相对标准偏差为1.52%~12.99%(n=6)。该方法简单快速、灵敏度高、结果准确、可靠,利用该方法可有效测定焙烤食品及其原料中常见真菌毒素的含量。     

通过式固相萃取/超高效液相色谱-串联质谱法快速测定动物源性食品中安乃近代谢物残留量

建立了通过式固相萃取/超高效液相色谱-串联质谱(UPLC-MS/MS)快速测定动物源性食品中4-甲氨基安替比林(MAA)、4-氨基安替比林(AA)、4-甲酰氨基安替比林(FAA)和4-乙酰氨基安替比林(AAA) 4种安乃近代谢物的方法。样品采用乙腈提取,PRiME HLB固相萃取柱净化,在ACQUITY BEH C_(18)色谱柱上以乙腈和0.1%甲酸水溶液为流动相梯度洗脱,超液相色谱-串联质谱MRM方式进行定量分析。结果表明,4种化合物在0.5～50μg/L范围内线性关系良好,相关系数(r)大于0.996,方法的检出限(LOD)为2μg/kg,定量下限(LOQ)为5μg/kg。4种化合物在3个加标水平(5、10和50μg/kg)下的回收率为75.1%～115%,相对标准偏差(RSD)为1.6%～7.4%。该方法简单、快速、准确,可实现动物源性食品中安乃近代谢物的快速测定。     

分散固相萃取净化/液相色谱-串联质谱法测定化妆品中7种氨基苯甲醚

建立了同时测定化妆品中7种氨基苯甲醚类化合物(邻氨基苯甲醚、间氨基苯甲醚、对氨基苯甲醚、2,4-二氨基苯甲醚、2,5-二氨基苯甲醚、3,4-二氨基苯甲醚、3,3'-二甲氧基联苯胺)的分散固相萃取净化液相色谱-串联质谱(LC-MS/MS)分析方法。样品用甲醇-水(1∶1,含0.1%甲酸)溶液提取,经PSA分散固相萃取净化后,样液经Welch Ultimats XB-C_(18)(4.6 mm×150 mm,5μm)色谱柱分离,多反应监测(MRM)模式检测,以保留时间和特征离子对定性,外标法定量。结果表明,7种氨基苯甲醚类化合物在0.10~200.0μg/L浓度范围内线性关系良好,相关系数均大于0.998;方法检出限(S/N=3)为0.4~10.9μg/kg。样品日内回收率为64.7%~98.1%,相对标准偏差(RSD,n=6)为1.2%~10.6%;日间精密度(n=5)为2.3%~9.8%。对30个不同水剂类化妆品检测发现,其中1个样品检出3,3'-二甲氧基联苯胺,含量为5.3μg/kg。该方法准确可靠,适用于化妆品中7种氨基苯甲醚的同时测定。     

HPLC-MS/MS法测定婴幼儿果蔬米粉中17种新烟碱类杀虫剂及代谢物

建立了婴幼儿果蔬米粉中17种新烟碱类杀虫剂及代谢物的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。样品经含1%(体积分数)甲酸的乙腈提取,QuEChERS净化,氮气吹干后,用含0.1%甲酸的乙腈水溶液(1∶4,体积比)定容。采用Acquity BEH C₁₈色谱柱(2.1 mm×100 mm,1.7μm)分离,0.1%甲酸水溶液和乙腈作为流动相梯度洗脱,高效液相色谱-串联质谱检测。结果表明,17种目标物在对应的质量浓度范围内线性良好,相关系数(r)均大于0.995 4;方法检出限(LOD)为0.02～0.15μg/kg,定量下限(LOQ)为0.06～0.50μg/kg;在LOQ、2.0μg/kg、10.0μg/kg 3个加标水平下,17种目标物在水果米粉中的平均回收率为62.5%～103%,相对标准偏差(RSD)为3.5%～17%;蔬菜米粉中的平均回收率为66.4%～108%,RSD为4.3%～13%。该方法灵敏、准确,简便、可靠,适用于婴幼儿果蔬米粉中17种新烟碱类杀虫剂及代谢物的同时检测。     

直接稀释/超高效液相色谱-串联质谱法测定河豚鱼与织纹螺中2种河豚毒素

建立了直接稀释/超高效液相色谱-串联质谱测定河豚鱼与织纹螺中2种河豚毒素TTX和4,9-anh TTX的方法。样品经乙酸-甲醇(1∶99)溶液提取,高速离心,上清液用80%(体积分数)甲醇水溶液稀释和过滤后直接进样分析。以0.5 mmol/L甲酸铵的0.1%甲酸水溶液-0.1%甲酸乙腈溶液为流动相,采用梯度洗脱方式在ACQUITY BEH Amide色谱柱(100 mm×2.1 mm,1.7μm)上分离,以电喷雾离子源正离子模式(ESI~+)扫描,多反应监测(MRM)模式采集,外标法定量。TTX和4,9-anhTTX分别在0.5～100μg/L、0.5～50μg/L质量浓度范围内呈良好的线性关系,相关系数(r~2)均大于0.99,检出限(LOD,S/N≥3)为100～150μg/kg,定量下限(LOQ,S/N≥10)为300～450μg/kg。在河豚鱼、织纹螺基质中,3个浓度水平下的加标回收率为75.4%～96.8%,日内相对标准偏差(RSD)为2.3%～9.5%,日间RSD为5.3%～9.2%。该方法简便、高效、节约成本,适用于河豚鱼、织纹螺中2种河豚毒素的快速准确检测。     

Furyl- and thienyl-silatranes and germatranes

We review our research on the synthesis and study of the physical and biological properties of furyl- and thienylgermatranes and -silatranes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 725–732, June, 1992.     

Review and patents and literature

The use of the insect cell/baculovirus expression system for producing recombinant proteins of bacterial, plant, insect, and mammalian origin has become widespread. The popularity of this eukaryotic expression system is due to many factors, including (1) potentially high protein expression levels, (2) ease and speed of genetic engineering, (3) ability to accommodate large DNA inserts, (4) protein processing similar to higher eukaryotic cells (e.g., mammalian cells), and (5) ease of insect cell growth (e.g., suspension growth). The following review of the literature discusses two engineering aspects of recombinant protein synthesis by insect cell cultures: bioreactor scale-up and insect cell line selection. Following this review patent abstracts and additional literature pertaining to expression of recombinant proteins in insect cell culture are listed.     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...     

Ground- and excited-state aromaticity and antiaromaticity in benzene and cyclobutadiene

The aromaticity and antiaromaticity of the ground state (S 0), lowest triplet state (T 1), and first singlet excited state (S 1) of benzene, and the ground states (S 0), lowest triplet states (T 1), and the first and second singlet excited states (S 1 and S 2) of square and rectangular cyclobutadiene are assessed using various magnetic criteria including nucleus-independent chemical shifts (NICS), proton shieldings, and magnetic susceptibilities calculated using complete-active-space self-consistent field (CASSCF) wave functions constructed from gauge-including atomic orbitals (GIAOs). These magnetic criteria strongly suggest that, in contrast to the well-known aromaticity of the S 0 state of benzene, the T 1 and S 1 states of this molecule are antiaromatic. In square cyclobutadiene, which is shown to be considerably more antiaromatic than rectangular cyclobutadiene, the magnetic properties of the T 1 and S 1 states allow these to be classified as aromatic. According to the computed magnetic criteria, the T 1 state of rectangular cyclobutadiene is still aromatic, but the S 1 state is antiaromatic, just as the S 2 state of square cyclobutadiene; the S 2 state of rectangular cyclobutadiene is nonaromatic. The results demonstrate that the well-known "triplet aromaticity" of cyclic conjugated hydrocarbons represents a particular case of a broader concept of excited-state aromaticity and antiaromaticity. It is shown that while electronic excitation may lead to increased nuclear shieldings in certain low-lying electronic states, in general its main effect can be expected to be nuclear deshielding, which can be substantial for heavier nuclei.     

微量元素与疾病诊断治疗的研究现状及展望

对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述，包括：微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。     

Preparation and photolysis of poly-p-ethylacrylophenone and poly-p-chloroacrylophenone and their copolymers with styrene and methyl methacrylate

Poly-p-ethylacrylophenone (PPEtAP) and poly-p-chloroacrylophenone (PPClAP) and their copolymers with styrene (PEtAP/S) and (PClAP/S) and with methyl methacrylate (PEtAP/MMA) and (PClAP/MMA) were prepared. Quantum yields of main-chain scissions at 366 nm at room temperature in benzene solution are of the same order as those of the unsubstituted polyacrylophenone and its copolymers. Substitution with chlorine and ethyl group in the para position compared to the unsubstituted polyacrylophenone and its copolymers leads to an increase of the lifetime for the n–π^* excited triplet state, as is evident from the measured quenching constants of photolysis. The low-temperature emission spectra of the copolymers are similar to the spectra of the model compounds in a polymer film. For the homopolymer, however, the character of the emission spectrum changes considerably.