毛细管电泳电致化学发光法同时测定氯丙嗪、异丙嗪及其主要代谢物

建立了同时检测氯丙嗪、异丙嗪及其主要代谢物的毛细管电泳电致化学发光新方法。最佳实验条件为: 检测电位1.20 V,钌联吡啶浓度5 mmol/L,检测池磷酸缓冲溶液40 mmol/L (pH 6.5),分离磷酸缓冲溶液18 mmol/L (pH 4.8),进样电压11 kV,进样时间8 s,分离电压13.5 kV。方法的检出限(3σ)分别为氯丙嗪8.3×10~7 g/L、异丙嗪7.2×10~6 g/L、氯丙嗪亚砜1.9×10~5g/L和异丙嗪亚砜3.7×10~6g/L,各组分的电化学发光强度和迁移时间的相对标准偏差(RSD)分别不超过3%和1%。本方法具有简便、快速、灵敏、进样量少和不受共存物干扰等特点,可在不必预分离的情况下直接同时连续测定家犬尿样中的氯丙嗪、异丙嗪、氯丙嗪亚砜和异丙嗪亚砜。     

动物源性食品中阿维菌素类药物残留的QuEChERS-液质联用法测定

建立了动物源性食品中阿维菌素、伊维菌素、多拉菌素、莫西菌素、埃普菌素、乙酰胺基阿维菌素6种阿维菌素类药物残留的高效液相色谱-串联质谱分析方法.样品采用乙腈提取,C18粉分散固相萃取净化,经ZORBAX Eclipse Plus C18(1.8 μm,2.1 mm×50 mm)色谱柱分离,电喷雾串联四极杆质谱在多反应离子监测方式下同时测定.6种分析物在0.002 ～0.1 mg/L范围内线性关系良好,相关系数均不低于0.991,方法的检出限(S/N≥3)为0.001 ～0.002 mg/kg;定量下限(S/N≥10)为0.002 ～0.005 mg/kg.猪肉基质中莫西菌素在0.005、0.01、0.02 mg/kg,其他化合物在0.002、0.005、0.01 mg/kg加标水平下,6种阿维菌素类药物的回收率为75% ～88%,相对标准偏差(RSD)为11.7% ～15.0%.该方法稳定、可靠,可满足动物源性食品中阿维菌素类药物残留检测与确证的需要.     

大鼠尿液中异丙嗪及其主要代谢物的GC-MS分析

采用气相色谱-质谱(GC-MS)分析了大鼠尿液中的异丙嗪及其代谢产物。尿液经β-葡萄糖醛酸酶酶解,Oasis(HLB 3 mL固相萃取柱提取后,以Restek R tx-5MS(30 m×0.25 mm×0.25μm)石英毛细管色谱柱为分析柱,经GC-MS分离检测。根据质谱图对代谢物的结构进行鉴定。结果表明:在大鼠尿液中检出了吩噻嗪、去甲基异丙嗪、异丙嗪亚砜、2-羟基去甲基异丙嗪、二羟基异丙嗪、顺-N-(1-丙烯基)吩噻嗪、反-N-(1-丙烯基)吩噻嗪、顺-N-(1-丙烯基)吩噻嗪砜、反-N-(1-丙烯基)吩噻嗪砜、顺-N-(1-丙烯基)吩噻嗪亚砜及反-N-(1-丙烯基)吩噻嗪亚砜11种代谢物。对异丙嗪在大鼠体内的氧化、还原等主要代谢途径进行了讨论。     

超高效液相色谱-串联四极杆质谱联用分析鸭蛋黄中的苏丹红Ⅰ～Ⅳ

建立了鸭蛋黄中苏丹红Ⅰ～Ⅳ号的超高效液相色谱-串联四极杆质谱联用（UPLC-MS/MS）的分析方法。采用乙腈提取样品中的苏丹红,加水反沉淀除去蛋白质和脂肪等杂质,冷冻后高速离心,取上层清液供UPLC-MS/MS分析。经Waters Acquity BHE C18超高效液相色谱柱分离,串联四极杆质谱多反应监测模式检测,4种物质的检出限均为0.05 μg/L,实际样品中4种物质的检出限为10 μg/kg。采用标准添加法测定苏丹红的回收率,100.0,200.0,300.0 μg/kg 3个不同添加水平的回收率为50.2%～101.3%。实验结果表明该方法灵敏度高,检出限低,确证能力强,分析时间短,可满足高通量食品样品中苏丹红的日常检测。     

超高效液相色谱-电喷雾串联质谱法测定饲料中残留的三聚氰胺

饲料样品经1%三氯乙酸-二甲基亚砜提取,Waters Oasis MCX柱净化,超高效液相色谱分离,最终采用电喷雾串联四极杆质谱进行检测。结果表明,三聚氰胺在饲料中的含量范围为10～5000 μg/kg时,线性关系良好(r＞0.99)。在10～100 μg/kg 的添加水平范围内的平均回收率为83%～94%,相对标准偏差为4.2%～6.5%。该方法的检出限为10 μg/kg。     

基质分散固相萃取-液相色谱-串联质谱法检测动物源性食品中硝基咪唑药物及其代谢物

建立了基质分散固相萃取-液相色谱-串联质谱（dSPE-LC-MS/MS）定量检测4种动物源性食品基质中硝基咪唑类药物及其代谢物的方法。样品（2.0 g）用乙酸乙酯提取后浓缩,经正己烷脱脂、50 mg乙二胺-N-丙基硅烷（PSA）吸附剂吸附净化后,过0.22 μm亲水聚四氟乙烯（PTFE）滤膜。采用C18柱分离,在电喷雾电离（ESI）源和选择反应监测（SRM）模式下检测,基质匹配内标法定量。在0.5~20.0 μg/L范围内,硝基咪唑类药物及其代谢物呈现良好的线性关系,相关系数（r²）>0.99;方法的检出限为0.1~0.5 μg/kg;在1.0、3.0和10.0 μg/kg的加标水平下,硝基咪唑类药物及其代谢物的回收率为84.2%~120.8%,相对标准偏差为2.0%~16.2%（n=6）。该法准确、快速,成本低,易操作,能够满足动物源性食品中硝基咪唑类药物及其代谢物残留的监测要求。     

超高效液相色谱-串联质谱测定猪肉中地塞米松、倍他米松和倍氯米松

提出了猪肉中糖皮质激素类药物地塞米松、倍他米松、倍氯米松同时测定的超高效液相色谱-串联质谱法(UHPLC-MS/MS),采用串联四极杆质谱仪及超高效液相色谱仪联用。质谱离子源为电喷雾电离,检测方式为多反应监测正离子模式。超高压反相C18色谱柱分离,以不同比例配成的甲酸-水(1+999)溶液及乙腈的混合溶液作流动相进行梯度洗脱。上述3种药物的质量浓度在1.0～100.0μg.L-1范围内呈线性。方法的回收率在83%～96%之间,地塞米松、倍他米松和倍氯米松的测定下限(10S/N)分别为1,1,2μg.kg-1。     

超高效液相色谱-电喷雾离子源-串联三重四极杆质谱分析饮用水中的高氯酸盐

建立了超高效液相色谱-电喷雾离子源-串联三重四极杆质谱(UPLC-ESI MS/MS)分析饮用水中高氯酸盐的方法.以300Extend-C18为分析柱,10%甲醇水溶液为流动相,ESI MS/MS串联质谱为检测器,以多重反应监测(MRM)模式监测高氯酸盐m/z 99.5→82.9离子对.方法的线性范围为0.2 ～10 μg/L,相关系数为r2=0.999 9,方法检出限为0.15 μg/L,平均加标回收率为82%,相对标准偏差为4.4%.应用UPLC-ESI MS/MS法测定北京市部分城区饮用水中的高氯酸盐,其中5个水样中检出ClO-4,质量浓度为0.040 ～0.262 μg/L,但在安全阈值范围内,不会对居民健康构成威胁.     

UPLC-MS/MS法对动物源性食品中12种大环内酯类抗生素残留的测定

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)法测定动物源性食品中12种大环内酯类抗生素(林可霉素、阿奇霉素、螺旋霉素、替米考星、竹桃霉素、红霉素、泰乐霉素、吉他霉素、罗红霉素、克拉霉素、麦迪霉素、交沙霉素)的方法.样品均质后,用乙腈提取,正己烷净化,无水硫酸钠脱水.乙腈提取液减压浓缩后,氮气流吹干,甲醇溶解定容;采用UPLC-MS/MS电喷雾多反应监测模式检测,基质匹配标准曲线定量.实验结果表明,12种大环内酯化合物在5 ～100 μg/kg范围内线性关系良好,检出限均为5.0 μg/kg,定量下限为10 μg/kg.5种空白基质样品中,10、25、50 μg/kg加标水平的平均回收率为60% ～117%,相对标准偏差均在20%以内.该方法灵敏度高、重复性好,各项技术指标均满足国内外相关法规要求,可用于动物源性食品中12种大环内酯类抗生素残留的检测.     

超高效液相色谱-串联质谱法测定猪肉中硝基呋喃类代谢物

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)测定猪肉组织中4种硝基呋喃类代谢物的分析方法.样品经盐酸水解,2-硝基苯甲醛衍生,乙酸乙酯提取净化,在正离子模式下以电喷雾电离串联质谱进行测定,内标法定量.在优化的实验条件下,4种代谢物在0.5~50μg/kg范围内线性良好,相关系数大于0.995,方法检出限为0.2μg/kg,定量限为0.5μg/kg.在0.5、1.0和10.0μg/kg的添加水平下,4种代谢物的平均回收率在74.6%~104.8%之间,相对标准偏差(RSD,n=6)在2.4%~15.6%之间.方法可应用于猪肉中4种硝基呋喃类药物代谢物残留的同时检测.     

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...     

Hard and soft acids and bases: structure and process

Under investigation is the structure and process that gives rise to hard-soft behavior in simple anionic atomic bases. That for simple atomic bases the chemical hardness is expected to be the only extrinsic component of acid-base strength, has been substantiated in the current study. A thermochemically based operational scale of chemical hardness was used to identify the structure within anionic atomic bases that is responsible for chemical hardness. The base's responding electrons have been identified as the structure, and the relaxation that occurs during charge transfer has been identified as the process giving rise to hard-soft behavior. This is in contrast the commonly accepted explanations that attribute hard-soft behavior to varying degrees of electrostatic and covalent contributions to the acid-base interaction. The ability of the atomic ion's responding electrons to cause hard-soft behavior has been assessed by examining the correlation of the estimated relaxation energies of the responding electrons with the operational chemical hardness. It has been demonstrated that the responding electrons are able to give rise to hard-soft behavior in simple anionic bases.     

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.     

Concentrations and distributions of trace and minor elements in Chinese and Canadian coals and ashes

A total of 35 trace and minor elements including some of environmental significance were determined in each of a selection of 15 Chinese and 6 Canadian thermal coals and their ashes by using the SLOWPOKE-2 nuclear reactor facility of the University of Toronto. The concentrations and distributions of these constituents among the coals and their combustion products (viz. ash and volatile matter) are presented together with an interpretation of their significance in relation to the large scale combustion of these coals as thermal fuels in industrialized countries such as China and Canada. The detailed results showed wide variations in trace impurity concentrations (up to a factor of 100 and more) among the coals studied with few large differences between those of Chinese and Canadian origin except that the rare earths, Sc, Th, U, I, and Se were much higher in the former, other halogens, As and Na were lower. Values for elemental enrichment factors (EF) relative to normal crustal abundances indicated that only As(EF=13), Br(5.7), I(16), S(230), Sb(11) and Se(320) were appreciably enriched in coal. During static ashing at 750°C most of the halogens, S and Se were volatilized whereas most other inorganic constituents were highly retained and concentrated in the ash by factors of 6 to 11.