气相色谱/质谱测定皮革及其制品中乙二醇醚类有机溶剂的残留量

建立了同时测定皮革及其制品中12种乙二醇醚类有机溶剂残留量的气相色谱/质谱-选择离子监测方法。以乙酸乙酯为萃取溶剂,在45℃下超声萃取皮革及其制品中的乙二醇醚类有机溶剂,萃取液经固相萃取柱净化后进行气相色谱/质谱-选择离子监测法测定,外标法定量。在信噪比（S/N）=3的条件下,乙二醇单乙醚（EGEE）的检出限为0.10 mg/kg,其余11种乙二醇醚类有机溶剂的检出限均小于0.05 mg/kg。在3个加标水平下,该方法的平均加标回收率为81.2%~95.5%,相对标准偏差（RSD）为1.4%~6.6%（n=9）。该方法简便快捷,灵敏度高,检出限远远低于欧盟法规《化学品的注册、评估、授权和限制》（REACH）的限量要求,适用于皮革及其制品中乙二醇醚类有机溶剂残留量的测定,为制定相关检测标准提供了参考。     

气相色谱-质谱法测定水产品中15种邻苯二甲酸酯类塑化剂的残留量

建立了同时测定水产品中15种邻苯二甲酸酯类塑化剂残留的气相色谱-质谱(GC-MS)分析方法。样品经二氯甲烷-正己烷(1∶1)混合溶液超声萃取,中性氧化铝玻璃层析柱净化,用正己烷、二氯甲烷-正己烷(1∶9)混合液、乙酸乙酯-正己烷(1∶4)混合液和乙酸乙酯依次洗脱目标物,洗脱液经浓缩后正己烷定容,气相色谱-质谱测定。结果显示,15种邻苯二甲酸酯的线性范围为0.05～1.0 mg/L,相关系数(r)不小于0.999 1,检出限(LOD,S/N=3)为0.04～1.18μg/kg,定量下限(LOQ,S/N=10)为0.20～4.00μg/kg,不同水产品样品中添加2、50、200μg/kg的15种PAEs,平均加标回收率为81%～123%,相对标准偏差(RSDs,n=3)均小于15%。该方法稳定、可靠、操作简便,适用于鱼肉等水产品中多种PAEs的同时检测与确证。     

合肥光源高亮度模式Lattice设计

介绍了一组合肥光源新高亮度模式的Lattice. 新的设计维持了储存环上所有元件和光束线位置不变,也没有加入新的元件. 取得了较低发射度. 所有直线节处的垂直方向β函数值都很小，适合插入件的运行. 跟踪计算表明新Lattice具有足够大的动力学孔径用于注入和储存粒子.     

Numerical simulation of the unsteady aerodynamic interaction of two plane airfoil cascades

A method for the calculation of unsteady aerodynamic interaction of two plane airfoil cascades that are in relative motion in a subsonic flow of ideal gas is developed. This interaction provides a two-dimensional approximation of the flow in a stage of an axial turbomachine. The method is based on the reduction of the problem to the calculation of the unsteady flow in a single interblade passage of each of the cascades. The calculation uses generalized space-time periodicity relations corresponding to the unsteady process of interest. The calculation is based on the direct numerical integration of the non-stationary gas dynamics equations with the use of the finite difference Godunov-Kolgan-Rodionov scheme of the second approximation order with respect to time and space. The calculation procedure includes the determination of the acoustic fields that are generated by the stage in the incident flow and in the flow behind it. The results of the calculations that illustrate the accuracy of the numerical solution and the capabilities of the method are presented.     

Effect of viscosity on stationary phase stability in capillary column gas chromatography

With recent advances in column technology it is now possible to prepare highly efficient, very inert, and thermally stable capillary columns coated with nonpolar polysiloxane stationary phases. Unfortunately, the same degree of success has not been achieved for some of the more polar polysiloxane phases. A parameter that has been studied little in the past in relation to stationary phase film stability is the viscosity of the stationary phase. In this paper the efficiency and stability of coated columns are correlated to the viscosity of the phase. Due to their structure, the viscosity of the phenyl-containing polysiloxanes change rapidly with temperature and hence, thin-film coatings are not stable at elevated temperatures. By using high viscosity phenyl-containing methylphenylpolysiloxanes which were recently synthesized, efficient and stable columns have been prepared.     

固相萃取结合超高效液相色谱-串联质谱法及气相色谱-负化学源质谱法测定人血清中的四溴双酚A、六溴环十二烷和多溴联苯醚

建立了固相萃取同时提取、净化血清中四溴双酚A(TBBPA)、α, β, γ-六溴环十二烷(HBCD)和8种多溴联苯醚(PBDEs)同系物的样本前处理方法,并结合色谱-质谱分离分析技术检测人血清样本中该类化合物的含量。试样在加入各自的同位素内标物后以甲基叔丁基醚/正己烷(1:1, v/v)混合溶剂进行萃取,再经浓硫酸去除脂肪后,以LC-Si固相萃取柱分离HBCD/TBBPA和PBDEs。采用分步检测的方式,在50 mm长BEH C18反相色谱柱上以超高效液相色谱-串联质谱(UPLC-MS/MS)的多反应监测模式(MRM)检测HBCD和TBBPA,在15 m长的毛细管柱上以气相色谱-负化学源质谱(GC-NCI/MS)的选择离子监测模式(SIM)检测PBDEs。以胎牛血清为空白基质,当HBCD、TBBPA和BDE-209的加标水平为0.5 ng/g和5 ng/g、三溴至七溴联苯醚的加标水平为0.05 ng/g和0.5 ng/g时,它们的平均加标回收率为80.3%～108.8%,相对标准偏差为1.02%～11.42%(n=5);以信噪比(S/N)为3计算,方法的检出限(LOD)为1.81～42.16 pg/g。采用该方法对实际样品进行测定,结果表明,本方法快速、准确、灵敏度高,能够满足血清中HBCD、TBBPA和PBDEs残留的同时提取及测定的要求。     

气相毛细管柱切割-反吹技术及归一化法分析汽油中的芳烃(英文)

 发展了一种采用毛细管气相柱切割 反吹技术分析汽油中芳烃的方法。利用强极性毛细管预柱将芳烃保留至n C10 的脂肪族化合物之后 ,并将其反吹到非极性毛细管柱中按沸点详细分离分析。该方法使预柱先流出的组分和分析柱流出的组分通过一个微型三通进入同一检测器中 ,因此可用归一化方法定量分析汽油中的芳烃。该方法可在 15min内完成汽油中苯至C10 芳烃的分析 ,结果的相对标准偏差 (RSD)≤ 3% ,切割误差为± 5s时分析结果的RSD≤ 4 %。     

Determining multi‐pesticide residues in teas by dispersive solid‐phase extraction combined with speed‐regulated directly suspended droplet microextraction followed by gas chromatography–tandem mass spectrometry

In this study, an effective speed‐regulated directly suspended droplet microextraction method was developed to condense pesticide residues from teas through dispersive solid‐phase extraction prior to analysis by gas chromatography with tandem mass spectrometry. The extractant was intentionally dispersed into the sample solution in the form of globules through high‐speed agitation. This procedure increases the contact area between the binary phases and shortens the distribution equilibrium time. The fine globules reassembled by decelerating stirring speed, the extractant could be taken out for gas chromatography with tandem mass spectrometry. Recovery studies were performed under optimized extraction conditions by using matrix blanks fortified with pesticides at three concentrations (10, 50, and 100 µg/kg). Over 87% of the recoveries for the analytes in four tea matrices were acceptable given their recovery ranges of 70–120% and relative standard deviations of ≤20%. The limits of quantification of most pesticides were lower than 10 µg/kg and thus satisfied the requirements for maximum residue levels prescribed by the European Community. A total of 38 tea samples from local markets were analyzed by using the proposed method. Results showed that chlorpyrifos was the most frequently detected pesticide in teas. The method is a potential choice for the routine monitoring of pesticide residues in complex matrices.     

同位素内标-气相色谱-高分辨双聚焦磁质谱法检测血清中多溴联苯醚

建立了同位素内标-气相色谱-高分辨双聚焦磁质谱(GC-HRMS)同时测定人体血清中14种多溴联苯醚(PBDEs)的方法.血清样品解冻后,取0.5 mL与13 C标记的内标物进行混合,加入甲醇沉淀样品中的蛋白质,比较了3种酸化条件下的去脂效果和回收率,结果显示硫酸去脂效果最好;使用液液萃取法提取样品中的目标物,比较了不同...