液相色谱-串联质谱法同时测定牙膏中16种磺胺类药物残留

建立了液相色谱-串联质谱法测定牙膏中16种磺胺类（磺胺间二甲氧嘧啶、磺胺-6-甲氧嘧啶、磺胺苯吡唑、磺胺二甲嘧啶、磺胺甲氧哒嗪、磺胺对甲氧嘧啶、磺胺吡啶、磺胺邻二甲氧嘧啶、磺胺甲基嘧啶、磺胺噻唑、磺胺甲基异噁唑、磺胺嘧啶、磺胺氯哒嗪、磺胺二甲异噁唑、磺胺甲噻二唑、磺胺醋酰）药物残留,试样经超声提取,Agilent poroshell 120 SB-C18色谱柱（3.0 mm×100 mm×2.7 μm）分离后,进行HPLC-MS/MS多反应监测模式下的定性及定量分析。16种磺胺类药物的方法检出限为2.0 mg/kg,在低、中、高3个添加水平范围内的平均回收率为81.2%~104.7%,相对标准偏差均小于9.1%。该方法简便、灵敏度高、重现性好、定性定量准确,适用于牙膏中磺胺类药物残留的测定。     

荧光胺衍生化液相色谱法检测动物肝脏中10种磺胺残留方法探讨

建立动物肝脏中常见的10种磺胺类药物(磺胺胍、磺胺嘧啶、磺胺二甲嘧啶、磺胺甲氧哒嗪、磺胺间甲氧嘧啶、磺胺-5-甲氧嘧啶、磺胺氯哒嗪、磺胺甲恶唑、磺胺二甲氧嘧啶、磺胺喹恶啉)残留量液相色谱同时测定方法。样品通过溶剂提取净化、荧光胺柱前衍生化,用配有荧光检测器的高效液相色谱仪测定,外标法定量。其线性范围分别为2～200μg/L、4～400μg/L、10～1000μg/L,线性相关系数r>0.999;方法检出限(LOD)为2～10μg/kg;其中9种磺胺,在5～100μg/kg的3个添加水平范围内的平均回收率为70.6%～90.2%;相对标准偏差为4.1%～7.6%。     

毛细管电泳法分离9种磺胺类药物

本研究建立了毛细管电泳法分离磺胺二甲嘧啶、磺胺氯哒嗪、磺胺吡啶、磺胺醋酰、磺胺噻唑、磺胺甲基嘧啶、磺胺喹恶啉、磺胺甲噻二唑和磺胺间二甲氧嘧啶的方法,测定了滴眼液和兽药药粉中相关磺胺类药物成分含量。毛细管为熔融石英毛细管(75/365μm,40/47cm),运行缓冲液为20mmol/L磷酸盐缓冲溶液(pH 7.5),电压8kV,柱温为20℃,检测波长210nm。9种磺胺类药物分离效果良好。在5～60μg/mL浓度范围内,磺胺类药物峰高和浓度的线性关系良好,相关系数R为0.9922～0.9990。测定滴眼液中磺胺醋酰钠含量以及药粉中磺胺氯哒嗪钠的含量,与标示量基本相符。该方法具有快速、简便、准确度高等特点,适用于磺胺类药物含量的测定。     

GC-TOF-MS技术快速鉴定抗风湿痛

应用高分辨GC-TOF-MS对抗风湿痛胶囊中的未知西药成分进行快速鉴定。使用不同极性的有机溶剂进行提取，将提取物分别离心，取上清液进行气质联用分析，并借助Nist2002数据库进行鉴定，用精确分子质量和元素分析进行确证。分析发现，此抗风湿痛胶囊中添加了甲氧苄氨嘧啶、磺胺甲恶唑、安定、可待因、茶碱等5种西药。用液质联用仪对甲氧苄氨嘧啶、磺胺甲恶唑进行了定量分析。该方法可用于未知混合物的分析，同样适用于中药制剂中其他西药成分的快速检出。     

QuEChERS-高效液相色谱-串联质谱法同时测定水产养殖环境沉积物中磺胺类、喹诺酮类、大环内酯类抗生素

建立了QuEChERS结合高效液相色谱-串联质谱同时测定水产养殖环境沉积物中磺胺类、喹诺酮类、大环内酯类等26种抗生素残留的分析方法。沉积物经20 mL乙腈-磷酸盐缓冲液（1∶1，V/V）超声提取，0.15 g乙二胺四乙酸二钠（Na-2EDTA）络合除杂，氯化钠（NaCl）盐析，无水硫酸镁（MgSO₄）、N-丙基乙二胺（PSA）、C18吸附剂和石墨化碳黑（GCB）填料净化，然后，通过Ultimate XB-C18色谱柱分离，采用4 mmol/L乙酸铵-0.1%甲酸水溶液和0.1%甲酸甲醇梯度洗脱，电喷雾正离子模式下，以多反应监测模式（MRM）监测，外标法定量。结果表明：在1.0~200 μg/L范围内，26种抗生素的线性相关系数均在0.99以上，方法定量限为1~2 μg/kg；在3个浓度添加水平下，平均回收率为60.4%~113%，相对标准偏差为1.5%~13.6%。该方法具有良好的精密度和准确度、灵敏度高、适用范围广，可在一定程度上实现这26种抗生素的多残留快速测定。采用该方法对某养殖区的20个养殖池塘沉积物进行检测，磺胺甲基嘧啶、磺胺二甲嘧啶、磺胺甲噁唑、磺胺嘧啶、红霉素、罗红霉素、克拉霉素均有检出，其中磺胺嘧啶、磺胺二甲嘧啶、磺胺甲噁唑的检出率较高。     

磺胺多辛乙胺嘧啶片微生物限度检查方法的建立

目的：完善磺胺多辛乙胺嘧啶片微生物限度检查方法。方法：采用薄膜过滤并在培养基中加入中和剂（1％的对氨基苯甲酸溶液）的方法,去除磺胺多辛的抗菌活性。结果：本方法满足中国药典2005版验证试验的基本要求。结论：该方法可作为磺胺多辛乙胺嘧啶片的常规微生物限度检查方法。     

CdTe量子点分子印迹传感器对水中磺胺类药物残留的检测

磺胺类抗生素被广泛应用于水产养殖,会对环境造成危害。为了检测水环境中该类药物的浓度,本研究合成了磺胺类药物量子点分子印迹传感器,用于快速检测水样中的磺胺类抗生素。在CdTe量子点表面,以磺胺嘧啶为虚拟模板,采用溶胶-凝胶法合成了具有良好光学性质的分子印迹荧光传感器。通过红外光谱(FT-IR)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)对传感器进行了表征,并测试了pH值对测定条件的影响,分析了传感器对不同药物的选择性。印迹聚合物成功接枝在了量子点表面,在pH为8.0时,具有最佳荧光吸收。在该条件下,当磺胺嘧啶在2~10μmol/L的浓度范围内,CdTe@SiO2@MIPs的荧光猝灭率(F0/F)随体系中磺胺嘧啶的浓度变化关系符合SternVolmer方程(R2=0.982 7,n=5)。加标回收率显示,磺胺嘧啶的回收率范围为90.0%~104.4%,相对标准偏差不超过14.7%。实验结果表明制备的CdTe@SiO_2@MIPs可快速灵敏地检测水样中磺胺类药物的残留。     

近红外光谱结合偏最小二乘法对甲氧苄啶粉末药品的定量分析

利用漫反射法获得甲氧苄啶粉末药品的近红外光谱（波长范围1100-2500nm）,采用化学计量学中的偏最小二乘法（PLS）及不同的光谱预处理方法（标准归一化（SNV）、一阶导数和二阶导数）对光谱进行信息提取和分析,对甲氧苄啶粉末药品进行了无损定量分析,以样品中甲氧苄啶为活性成分建立了最佳的数学校正模型。同时讨论了主成分数对PLS模型定量预测能力的影响,并对所得结果做出了比较。     

高效液相色谱法测定猪肉中五种磺胺类药物残留量

建立了高效液相色谱法测定猪肉中的磺胺间甲氧嘧啶(SMM)、磺胺二甲基嘧啶(SM,)、磺胺甲噁唑(SMZ)、磺胺二甲氧嘧啶(SDM)和磺胺喹噁啉(SQ)五种磺胺类药物残留的方法.研究了五种磺胺类药物残留的提取、净化和色谱条件.样品经乙腈提取,经乙腈饱和的正己烷液一液分配,以Symmetry C18为分离柱,乙腈-1%乙酸为流动相,于270nm波长处检测,外标法定量.结果表明,五种磺胺类残留药物能在35min内得到有效分离,峰形对称.最低检出限为5μg/kg(3倍噪声),样品的加标回收率为80.1%～96.5%.     

DSC-显微镜系统的药学应用

热台DSC-显微镜系统是对药物和有机材料的各种热转变进行图像和热分析同步表征的的强大工具。本文以磺胺药物类之一的磺胺嘧啶的多晶态转变分析为例，介绍了热台DSC-显微镜系统在药物研究和分析方面的应用。[编者按]     

精密步进滚珠丝杠副的研制

本文主要阐述精密步进滚珠丝杠副的工作原理、结构设计、制造工艺及精度检验.本文阐述的步进滚珠丝杠副已应用于北京质子加速器的束流测量系统中.步距为055mm;步距精度为0.01mm;步进速度为6mm/s.该滚珠丝杠副是双螺母外循环方式的,循环组数为1组2.5圈.丝杠直径为20.5mm;导程为5mm;滚珠直径为3,175mm;定位精度为4.7μm;复位精度为2.0μm.     

Upstream installation and misalignment effects on the performance of a modified electromagnetic flowmeter

The performance of a modified Danfoss 50 mm diameter electromagnetic flowmeter has been investigated when installed downstream from three different pipe diameters—50 mm, 55 mm and 45 mm. The effects of a 3 mm misalignment of the flowmeter, in both the vertical and horizontal planes, with respect to each of the three upstream pipe diameters has also been identified. The largest percentage errors are reported for the 45 mm upstream diameter pipe, with the flowmeter misaligned by 3 mm in the horizontal plane. The vertical and horizontal mean velocity and root-mean-square velocity profiles, measured within the flowmeter using laser Doppler anemometry, show significant variations in comparison with the ideal, fully developed profiles.     

核反应堆厚壁压力容器焊缝TOFD检测缺陷高度分辨率探究

对壁厚220 mm的核反应堆压力容器焊缝超声衍射时差法（ TOFD ）检测中缺陷高度分辨率进行理论分析,绘制了缺陷高度分辨率随缺陷埋深变化的函数曲线。当缺陷高度小于系统高度分辨率时,提出利用基于傅里叶变换的频谱分析法测算缺陷高度。3个侧通孔（埋深22.5 mm,Ф3.0 mm;埋深40.0 mm,Ф2.0 mm;埋深80.0 mm,Ф2.0 mm）的试验分析结果验证了该方法的有效性。进一步的数值计算结果表明,对埋深182.0 mm,Ф2.0 mm侧通孔的TOFD检测信号进行频谱分析,能够准确确定缺陷高度。     

小型数控微细铣床的研制及铣削试验研究

总结了现有微小零件加工技术的局限性,阐述了微细铣削加工的优势,并自主构建了一台适于微小零件制造的小型三轴数控微细铣床,铣床本体尺寸为400mm×400mm×260mm,工作空间为50mm×50mm×50mm。介绍了组成微细铣床的六大子系统的性能,对微细铣床系统进行精度测试,该铣床的定位精度达到1μm,满足微细铣削加工的精度要求。使用硬铝LY12进行微直槽及薄壁、微同心圆槽的铣削加工试验。加工试验结果显示:该微细铣床已经具备加工介观尺度的高深宽比微小零件的能力。     

红外线聚光非球面透镜的单点金刚石镜面切削方法

根据硬脆性材料的延性域加工机理和面形误差补偿加工方法,研究了圆弧形和平头形刀具的单点金刚石延性域切削方法,在加工中直接获得了镜面切除面;并利用数控技术进行误差补偿,克服了因加工试验、刀具磨损、机械振动、热变形等造成的加工误差导致的非球面的面形精度降低和表面粗糙度恶化.并将该方法用于采用圆弧形刀具对红外线聚光的φ70mm非球面锗透镜进行单点金刚石切削实验中.试验结果表明面形误差补偿加工方法可以进一步消除加工误差,将非球面的面形精度PV值从微米级(1.23μm)提高到亚微米级(0.36μm)的程度,表面粗糙度R_a从亚微米级(0.27μm)改善到超亚微米级(0.04μm)的范围.     

小型数字投影结构光三维测量仪镜头设计

为了解决三维测量仪器的小型化问题,设计了一种数字投影结构光三维测量仪光路结构,并用Zemax软件进行了性能优化。该结构分为投影光路和照相光路,投影镜头采用反远距结构,由5片透镜组成,全视场调制传递函数大于0.35。照相镜头采用双高斯结构,由6片透镜组成,全视场调制传递函数大于0.12。两镜头口径均小于14mm,长度小于40mm,像面照度均大于90%,可以对80~120mm远的物体进行测量。投影图像像素密度为1 028×768,相机拍摄图像像素密度为1 280×960,在工作距离100mm处可以测量28mm×21mm的表面。镜头全部采用球面透镜。该结构具有测量精度高、成本低、加工容易、体积小等优点。     

Measurement of thermal conductivity of fluid using single and dual wire transient techniques

A modified measurement device to measure thermal conductivity of fluids using transient hot-wire technique has been designed, developed, tested and presented in this paper. The equipment is designed such that the thermal conductivity could be measured using both single wire sensor of different length and dual wire sensor. The sensor, which is also a heater, is a platinum micro-wire of 50 μm diameter. The influence of wire length on the measurement of thermal conductivity of fluids is tested using two single wires of length 50 mm and 100 mm. The thermal conductivity is also measured using a dual hot wire arrangement; which is achieved by placing the 100 mm and 50 mm wires in a Wheatstone bridge with the 100 mm wire as the sensor and 50 mm wire as a compensation wire. The apparatus requires a 100 ml of test fluid to perform the experiment. The testing temperature of the test fluid during the experimentation can be suitably varied by the choice of heat exchange fluid used in the apparatus. Water is chosen as testing fluids for primary standards. When compared to single wires, the thermal conductivity of the fluids measured is consistent with dual-wire method with an uncertainty of ±0.25%.     

Plane kinematic calibration method for industrial robot based on dynamic measurement of double ball bar

A new calibration method is proposed to improve the circular plane kinematic accuracy of industrial robot by using dynamic measurement of double ball bar (DBB). The kinematic model of robot is established by the MDH (Modified Denavit-Hartenberg) method. The error mapping relationship between the motion error of end-effector and the kinematic parameter error of each axis is calculated through the Jacobian iterative method. In order to identify the validity of the MDH parameter errors, distance errors and angle errors of each joint axis were simulated by three orders of magnitude respectively. After multiple iterations, the average value of kinematic error modulus of end-effector was reduced to nanometer range. Experiments were conducted on an industrial robot (EPSON C4 A901) in the working space of 180 mm × 490 mm. Due to the measuring radius of DBB, the working space was divided into 30 sub-planes to measure the roundness error before and after compensation. The average roundness error calibrated by the proposed method at multi-planes decreased about 21.4%, from 0.4637 mm to 0.3644 mm, while the standard deviation of roundness error was reduced from 0.0720 mm to 0.0656 mm. In addition, by comparing the results of positioning error measured by the laser interferometer before and after calibration, the range values of motion errors of end-effector were decreasing by 0.1033 mm and 0.0730 mm on the X and Y axes, respectively.     

A stereovision model applied in bio‐micromanipulation system based on stereo light microscope

A bio‐micromanipulation system is designed for manipulating micro‐objects with a length scale of tens or hundreds of microns based on stereo light microscope. The world coordinate reconstruction of points on the surface of micro‐objects is an important goal for the micromanipulation. Traditional pinhole camera model is applied widely in macrocomputer vision. However, this model will output bad data with remarkable error if it is directly used to reconstruct three‐dimensional world coordinates for stereo light microscope. Therefore, a novel and improved pinhole camera model applied in bio‐micromanipulation system is proposed in this article. The new model is composed of binocular‐pinhole model and error‐correction model. The binocular‐pinhole model is used to output the basic world coordinates. The error‐correction model is used to correct the errors from the basic world coordinates and outputs the final high‐precision world coordinates. The results show that the new model achieves a precision of 0.01 mm in the X direction, 0.01 mm in the Y direction, and 0.015 mm in the Z direction within a maximum reconstruction distance of 4.1 mm in the X direction, 2.9 mm in the Y direction, and 2.25 mm in the Z direction, and that traditional pinhole camera model achieves a lower and unsatisfactory precision of about 0.1 mm.     

Magneto-rheological engine mount design and experimental characterization

Isolation mounts using magneto-rheological (MR) fluid have increasing potential for various applications. This paper introduces new design and manufacturing aspects of MR engine mounts. CAD software was used to design MR mounts and three different types of MR mount prototypes were considered. Later, magnetostatic analyses were performed to validate the designed configuration of the electromagnetic coil, which controlled the MR fluid flow. The MR mounts were manufactured and, then, tested statically and dynamically using a servo-hydraulic rate machine. Static tests were performed with amplitudes between 0–10 mm. Dynamic tests were performed under excitation frequencies in between 0–100 Hz with amplitudes of ±0.1 mm, ±0.5 mm, ±1.0 mm and ±2.0 mm as well as under excitation frequencies in between 0–20 Hz with amplitudes of ±3.0 mm, ±4.0 mm. Besides the MR mounts, hydro mount and elastomeric top were tested adopting the same procedure. The finding of different mount properties was explained and MR mount characteristics in frequency domain were demonstrated. In addition, the measured characteristics were compared with each other for hydraulic mount and elastomeric top.