量热器阵列探测器

本工作研制出 5×25=125量热器阵列探测器。每个量热器单元是由石墨块与镍铬——镍铝热电偶构成。解决了热电偶丝与石墨块的粘接问题和上百条热电丝从真空室引出问题。创立了以液氮沸点温度为温度基点的新“0”点装置,它既具有温度稳定性能好又能解决各路之间的绝缘问题。为多路量热器mV级小讯号的物理测量奠定了基础。 采用Fy-1微机数据采集系统测量探测器的讯号。它性能稳定、采集速度快。测量了大面积二极管产生的电子束的均匀性,数据经过模拟处理,给出电子束空间分布的立体图像,从图可以清楚地看出电子束能量空间分布的非均匀性和轴向箍缩效应。     

气体基本定律在建立气体测量仪计量检定装置中的应用

遵循道尔顿定律建立的双压力法恒湿气体发生器,各项技术指标高于湿度计量一等标准要求,可用于校准和测量湿度仪器及测湿元件;遵循理想气体状态方程及静态容积法配制乙醇标准气体,建立的呼出气体酒精含量探测器检定装置,其不确定度优于被检探测器允许相对误差的三倍以上,可以满足呼出气体酒精含量探测器检定的需要。     

Determination of organic colorants in cosmetic products by high-performance liquid chromatography

Summary High-performance liquid chromatography (HPLC) with UV-vis detection was used for the determination of organic colorants in cosmetic products. 126 colorants were characterized by their retention times in an ion-pair reversed-phase HPLC system with gradient elution, and by their UV-vis spectra, recorded with a diode array detector (DAD). The method is rapid and efficient, as is demonstrated by the analysis of 45 cosmetic samples.     

Carbon response characteristics of a micro-flame ionization detector

The carbon response characteristics of a recently noted micro-flame ionization detector (μFID) mode are examined in detail. The μFID supports an extremely small (30 nL) “upside-down” flame that is generated from a low counter-current flow of oxygen immersed in hydrogen. Ionization measurements made in the μFID are directly compared to those obtained from a conventional FID. In terms of reproducibility of response and relative sensitivity towards different types of hydrocarbons, the μFID and a conventional FID produce no major differences with respect to either of these characteristics for a variety of compounds examined. Of note, for replicate measurements made in each detector, the average %R.S.D. of response typically differs by less than 2% between the two devices, while the average normalized sensitivity differs by less than 4%. In contrast to this, regarding absolute sensitivity, the analyte signal from the conventional air-rich FID is found to be three times larger than that of the hydrogen-rich μFID mode explored here. This discrepancy is ascribed directly to the difference in flame stoichiometry between the two detectors.     

高效液相色谱-蒸发光散射检测器测定食品中胆固醇含量

建立了可满足各类食品（包括动物性食品、动植物混合食品）中胆固醇的HPLC—ELSD快速测定方法。样品经50％（w）KQH直接皂化和石油醚萃取后进行色谱分析。色i普柱为ODS柱，流动相为乙醇和乙脯，通过优化梯度洗脱条件，在20min内实现了胆固醇与干扰物质（如植物甾醇）的有效分离，分离度月大于1．5。胆固醇色谱峰面积的自然对数与浓度的自然对数呈良好的线性关系（r〉0．9996），检出限（LOD）为0.20μg（S／N=3），定量下限（LOQ）为0．56μg（S／N=10），回收率为93％-96％（n=6），重复性RSD〈3．0％（n=6）。     

高效液相色谱-荧光法测定对虾组织中红霉素的残留量

建立了高效液相色谱-荧光法测定对虾组织中红霉素残留量的检测方法。主要研究了样品前处理方法。提出了以乙腈为提取剂，正己烷去脂、二氯甲烷反萃的新的样品处理方式。该方法简单，灵敏度高，方法检出限为150μg／kg，回收率≥75％。     

HPLC检测器的线性动态范围及其测试方法的研究

简单论述了ＨＰＬＣ检测器（ＨＰＬＣＤ）的线性动态范围（ＬＤＲ）的重要性，提出了对光学式ＨＰＬＣＤ的ＬＤ测试的一种新方法，同时对有关问题进行了讨论。     

非水介质毛细管电泳电化学检测日夜百服宁中的有效成分

用非水毛细管电泳电化学检测法分离检测了日夜百服宁中的有效成分，研究了电极电位，不同浓度的甲酰胺（FA），电解液浓度和酸度，电泳电压及进样时间对电泳分离的影响，得到了较为优化的测定条件。实验结果表明，在25mmol/L Tris-25mmol/L H3BO3(表观pH=8.5)运行介质中，日夜百服宁中的4种有效成分即扑热息痛（AP），盐酸伪麻黄碱（PH），氢溴酸右美沙芬（DM）和扑尔敏（CM）在12min内完全分离，检测电位为＋0．9V(vs.SCE)。线性范围分别为AP 0．5－200mg/L;PH 0.8-300mg/L;DM2.5-350mg/L;CM0.5-330mg/L；检测限分别为AP0.1mg/L;PH0.55mg/L;DM1mg/L;CM0.2mg/L。     

Rapid and ultra-sensitive GC/MS analyses with a microchannel plate array detector Part I: Possibilities of simultaneous ion detection in narrow-bore GC/MS

Identification and detection limits for scanning and non-scanning mass spectrometers are discussed. It is theoretically deduced and experimentally confirmed that these limits are on the low pico-and femtogram levels, respectively, when using conventional secondary electron multiplier-amplifier systems. The sensitivity can be increased at least tenfold by pulse-counting techniques, instead of current amplification, provided the chemical noise is sufficiently low. The potential advantages of a detection system for simultaneous ion detection in a significant mass range, for obtaining complete mass spectra in fast GC/MS analyses, are demonstrated. A double focusing mass spectrometer was constructed, using the well-proven Mattauch-Herzog principles. By application of an “electronic photoplate”, substance identification in the low femtogram range on a millisecond time scale, so far only accessible for single ion monitoring techniques, is feasible.     

亚临界水-火焰离子化检测-柱后分流色谱分离某些醇、酚和羧酸类化合物

采用柱前预热和柱后分流技术,构建了亚临界水-氢火焰离子化检测器色谱系统(SubWC-FID)。采用Polymerx RP-1聚合物色谱柱和纯水流动相,在亚临界状态下(柱温160~210℃),分离了某些醇、酚和羧酸类化合物,优化了FID稳定工作条件,考察了柱温、流动相流速和分流比对样品分离的影响。结果表明:在不高于1.48mL/min的流动相流速下,柱后分流模式的FID系统能稳定工作,方法的线性动力学范围在2~3个数量级之间,在分流比为1∶20时,乙醇、苯酚和乙酸的检出限分别为17、54和68ng。