固相萃取-液相色谱-质谱/质谱法同时测定蜂蜜中的多类药物残留

建立了采用固相萃取-液相色谱-质谱/质谱(SPE-LC-MS/MS)对蜂蜜中磺胺类、硝基咪唑类、喹诺酮类、大环内酯类、林可酰胺类和吡喹酮共计6大类54种药物残留同时测定的方法。蜂蜜经磷酸盐缓冲溶液(pH 8)稀释,Oasis HLB固相萃取柱净化后,通过液相色谱-质谱联用技术进行检测(正离子方式,多反应监测模式)。采用同位素稀释内标法或外标法进行定量,线性关系良好,相关系数大于0.992。方法的定量限(LOQ,以信噪比(S/N)大于10计)分别为磺胺类和硝基咪唑类药物1.0 μg/kg,喹诺酮类和林可酰胺类药物2.0 μg/kg,大环内酯类药物3.0 μg/kg,吡喹酮0.3 μg/kg。总体回收率为32.6%～114%,相对标准偏差为1.3%～28.9%。该方法的定量限满足目前国内外药物的最大残留限量要求,可作为蜂蜜中相关药物残留量的筛选检测方法。     

同位素稀释液相色谱-串联质谱法准确测定猪肉中的氯霉素

建立了同位素稀释质谱测定猪肉中氯霉素残留的方法,对影响溶剂提取、萃取净化、液相色谱-质谱检测方法准确度的因素进行了量化与优化。猪肉样品经液氮冷冻粉碎,加入氯霉素-D5同位素内标和0.1 mol/L醋酸钠缓冲溶液(pH 5),用乙酸乙酯提取4次,正己烷脱脂,HLB固相萃取小柱净化后采用负离子多反应监测模式下的液相色谱-质谱技术检测。方法的线性范围为0.01～0.5 ng/g,相关系数r2大于0.999;检出限和定量限分别为0.004 ng/g和0.02 ng/g;在0.02 ng/g和1.0 ng/g加标水平的回收率(n=3)分别为95.2%～109.1%和99.7%～102.5%;日内和日间相对标准偏差均小于2%。研究了氯霉素及氯霉素-D5的基体效应,测得不同流动相和稀释溶剂组成时基体效应因子k的范围在0.950～1.015之间。研究结果对同位素稀释质谱痕量残留检测结果准确度的控制、方法的建立与验证具有参考意义。     

超高效液相色谱-串联质谱法测定蜂蜜中甲硝唑

采用超高效液相色谱-串联质谱法测定蜂蜜中甲硝唑的含量。蜂蜜样品经磷酸氢二钾溶液溶解,乙酸乙酯提取,用MCS固相萃取柱净化。以Hypersil Gold-C_(18)色谱柱为分离柱,以不同体积比的0.1%(体积分数)甲酸溶液和乙腈混合液为流动相进行梯度洗脱,采用电喷雾正离子源多反应监测模式检测。以D4-甲硝唑为内标物。甲硝唑的线性范围为0.5~64.0μg·L~(-1),方法的测定下限(10S/N)为0.15μg·kg~(-1)。以空白样品为基体进行加标回收试验,所得回收率在95.6%~98.8%之间,测定值的相对标准偏差(n=6)在4.2%~8.3%之间。     

高效液相色谱-串联质谱联用测定蜂蜜中3种硝基咪唑类残留

1 引言 甲硝唑、二甲硝唑和洛硝哒唑是属于常用硝基咪唑类药物，用于预防和治疗特定病菌和原生动物疾病。由于硝基咪唑类化合物具有潜在的致癌性、诱导有机突变性，故欧盟和我国已禁止在任何动物源性食品中使用该类药物。目前测定硝基咪唑类的方法主要有气相色谱法和气相色谱-质谱联用法、高效液相色谱法和高效液相色谱-质谱联用法。本实验利用高效液相色谱-串联质谱联用测定蜂蜜中甲硝唑、二甲硝唑和洛硝哒唑3种硝基咪唑类残留。通过不同固相萃取及液相萃取比较，选择简便快捷的液相萃取方法，适合大量样品同时处理。同时比较使用了2种不同氘代内标，最终选择定量效果好的氘代二甲硝唑作为内标。     

超高效液相色谱-串联四极杆质谱法测定水产品中氯霉素残留量

建立超高效液相色谱-串联四极杆质谱法测定水产品中氯霉素残留量的方法。样品均质后经乙酸乙酯提取,正己烷脱脂(或用固相萃取柱净化),超高效液相色谱分离,串联四级杆质谱检测,同位素内标法定量。方法在0.05～1.0μg/kg的添加范围内的平均回收率为84.9%～103.3%,相对标准偏差为3.2%～5.2%,定量检测限为0.02μg/kg。方法适用于各种水产品基质的氯霉素残留检测。     

高效液相色谱-串联质谱法同时测定蜂王浆中氯霉素、甲砜霉素和氟甲砜霉素残留

采用高效液相色谱-串联质谱(HPLC-MS/MS)法同时测定了蜂王浆中氯霉素、甲砜霉素和氟甲砜霉素残留。样品加入阴性蜂蜜和水均质后,采用乙酸乙酯提取,蒸发浓缩,C18固相萃取净化。HPLC分离后,串联质谱法以电喷雾负离子多反应监测方式(MRM)进行定性定量分析。通过对固相萃取条件的优化,大大减小了基质的干扰。氯霉素、氟甲砜霉素和甲砜霉素的检出限分别为0.1 ng/g0、.2 ng/g和0.5 ng/g,平均回收率为89.9%~98.4%,相对标准偏差(RSD)均小于8.2%。     

高效液相色谱-串联质谱法测定蜂蜜中9种农药残留

建立了同时测定蜂蜜中9种苯并咪唑类和新烟碱类农药的全自动固相萃取-高效液相色谱-串联质谱检测方法。蜂蜜样品用磷酸盐缓冲液（pH=7.8）溶解，超声提取，经亲水亲脂平衡（hydrophilic-lipophilic balance，HLB）固相萃取小柱净化，氮吹浓缩，定容，过滤膜后进行高效液相色谱-串联质谱分析，采用多反应监测（MRM）模式测定，以内标法定量。结果表明，在0.002~0.05 mg/L范围内9种农药呈现出较好的线性关系（相关系数r² ≥ 0.99），检出限和定量限分别为0.1~1.0 μg/kg和0.3~2.0 μg/kg。对阴性蜂蜜，在5.0、10.0、20.0 μg/kg 3个水平下分别进行加标回收试验，测出9种农药的平均回收率在78.2%~101.2%之间，相对标准偏差为1.3%~14.3%（n=6）。该方法可适用于大批量蜂蜜样品的快速准确测定。     

超高效液相色谱-串联质谱法同时测定蜂蜜中硝基咪唑类、磺胺类、喹诺酮类兽药残留

建立蜂蜜样品中硝基咪唑类、磺胺类、喹诺酮类共36种兽药残留的固相萃取-超高效液相色谱-串联质谱检测方法。蜂蜜样品用H3PO4溶液(体积分数0.1%)溶解后,过滤,用Oasis HLB和PSA固相萃取柱净化,外标法定量。测定时用Eclipse Plus C18色谱柱(100 mm×2.1 mm,1.8μm)分离,乙腈-甲醇-甲酸溶液梯度洗脱,质谱测定采用多反应监测(MRM)模式。36种兽药的检出限在0.4～4.0 ng/mL,回收率在63.2%～125.5%,相对标准偏差均低于22%。     

磁性多壁碳纳米管固相萃取/高效液相色谱-串联质谱法测定蜂蜜中多组分兽药残留

建立了以磁性多壁碳纳米管为吸附剂的分散固相萃取/高效液相色谱-串联质谱检测方法,对蜂蜜中3大类44种兽药残留进行测定。样品经pH 4.0的Na2EDTA-Mcllvaine缓冲液提取,加入自制磁性多壁碳纳米管吸附目标物。目标物经10%氨水-甲醇洗脱后,液相色谱-串联质谱MRM模式进行定性定量分析。44种药物在1~40 ng/m L浓度范围内线性关系良好,相关系数均大于0.99;在3个不同浓度添加水平下,回收率为78.0%~105.1%,相对标准偏差(RSD)为1.2%~8.9%,检出限为0.2~2.0μg/kg。结果表明,该方法简单方便,易于操作,为蜂蜜中磺胺类、喹诺酮类以及硝基咪唑类兽药残留的测定提供了新途径。     

分散固相萃取-同位素稀释-高效液相色谱-串联质谱法同时测定猪肉中26种β-受体激动剂

建立了分散固相萃取-同位素稀释-高效液相色谱-串联质谱(dSPE-ID-HPLC-MS/MS)同时测定猪肉中26种β-受体激动剂残留的方法。样品经β-葡萄糖醛苷酶/芳基硫酸酯酶水解12 h后,用高氯酸沉淀蛋白质,取上清液,调节pH值为9,用乙腈涡旋提取,分散固相萃取净化。选用具有混合分离模式的新型色谱柱Poroshell 120Phenyl-Hexyl(100 mm×2.1 mm,4.0μm)对待测物进行分离,在电喷雾离子(ESI)源正离子模式下以多反应监测(MRM)模式采集数据并做定性筛查和定量分析。26种待测物在相应的浓度范围内线性关系良好,相关系数均大于0.99,在3个不同浓度的添加水平下,平均回收率为65.3%~108.5%,相对标准偏差(RSD)为2.7%~13.3%,检出限(LOD,S/N=3)和定量限(LOQ,S/N=10)分别为0.03~0.1μg/kg及0.1~1.0μg/kg。该方法成本低廉、灵敏可靠,适用于同时对猪肉产品中26种β-受体激动剂残留进行定性和定量筛查。     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

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...     

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。     

Ferrocene and ferrocenium modified clays and their styrene and EVA composites

In this work, ferrocene- and ferrocenium-containing salts were employed to modify montmorillonite. X-ray measurements show an increase in the interlayer spacing upon clay modification, which means that the larger and more organophilic cations were inserted into the gallery space of montmorillonite. Attempts to prepare nanocomposites of polystyrene and ethylene vinyl acetate copolymers lead to immiscible systems; the morphology of these systems was elucidated with TEM, XRD and cone calorimetry. The thermal stability of the composites is greater than that of the virgin polymer.     

Synthesis and Optical and Redox Properties of Symmetric and Asymmetric BODIPYs

Herein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission.     

Conformations and steric and stacking interactions of trisubstituted ureas and thioureas with alkyl and phenyl groups

The monomeric ν(N—H) vibrations of various trisubstituted ureas of the R₂UPh type and -thioureas of the R₂TUPh type have been studied. The trans—out isomerism in the former and the trans—out—cis isomerism in the latter are discussed from the point of view of steric effect. The monomeric ν(N—H) vibrations of RPhUPh and RPhTUPh are also examined. The single band appearing in the spectrum of both ureas is characteristic of the cis form; this suggests the existence of phenyl—phenyl interaction (the stacking interaction proposed by Galabov et al. [10]). Behavior of ν(N—H) vibrations at several concentrations is shown to be clearly different in the three forms (trans, out and cis). The presence of the cis form is confirmed by solvent effect experiments.     

含茂基苯并三氮唑基镧系有机配合物的合成及表征

三茂基镧系化合物和苯并三氮唑在四氢呋喃中反应,合成了7个未见文献报道的含茂基苯并三氮唑基镧系有机配合物,经元素分析、IR和MS测定,从有关数据推测了这类配合物的可能结构。     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。