5—氯水杨酸工业品的高效液相色谱分析

本文研究了用反相高效液相色谱法测定５－氟水杨酸工业品及其杂质水杨酸，３－氯水杨酸和３，５－二氯水杨酸含量的方法。样品在ＯＤＳ柱上进行分离，流动相为甲醇－稀高氯酸水溶液，紫外２２６ｎｍ，方法简单快速，结果准确可靠。     

气相色谱法测定3-氯-4-氟苯胺的含量及有关物质的方法研究

本文采用气相色谱法,用聚二乙二醇丁二酸脂(P.DEGS)为固定液的色谱柱,对3-氯-4-氟苯氨中可能存在的五种杂质进行了很好的分离,并以对溴苯胺为内标物,对3-氯-4-氟苯氨进行了含量测定。方法简便,结果准确。     

7-氯-2-氧代庚酸乙酯的GC分析及

采用气相色谱法对7-氯-2-氧代庚酸乙酯产品进行纯度测定,同时分离并分析了其中主要的微量杂质,该杂质为7-氯-2-氧代庚酸乙酯生产过程中产生的副产物。采用气相色谱-质谱联用法对7-氯-2-氧代庚酸乙酯产品进行了分析,通过解析7-氯-2-氧代庚酸乙酯及其主要杂质的质谱数据推断出该杂质为6-氯己醛。     

多元系数校正分光光度法同时测定萘,α-氯萘和β-氯萘

本文研究了蔡,α-氯茶和β-氯萘在环己烷中的紫外吸收光谱,建立了该三组分同时测定的多元系数校正分光光度法,回收率在90％～109％之间,相对标准偏差小于1％,并与经典解三元方程组法进行了比较,结果满意。     

HPLC法同时测定阿司匹林咀嚼片中阿司匹林和水杨酸的含量

目的用高效液相色谱法同时测定阿司匹林咀嚼片中阿司匹林和水杨酸的含量.方法采用VP-ODS色谱柱;以甲醇-醋酸-水(45∶1∶54)为流动相;流速1ml/min,检测波长为275nm.结果阿司匹林线性范围0.54～10.85μg(γ=0.99996),平均回收率为98.3%,RSD为0.76%(n=5);水杨酸线性范围2.65～31.77μg/ml(γ=1.00000),平均回收率为100.2%,RSD为0.53%(n=5).结论此方法简便、快速、准确,值得推广应用.     

高效液相色谱-串联质谱法检测动物源食品中硝呋索尔代谢物残留

建立动物源食品中硝呋索尔代谢物3,5-二硝基水杨酸肼（DNSH）残留量的液相色谱 串联质谱（LC-MS/MS）检测方法。样品经盐酸水解,2-硝基苯甲醛衍生,提取净化后,用液相色谱 电喷雾三重四极杆串联质谱检测,多反应监测模式（MRM）优化质谱参数,内标法定量。该方法的线性范围为0.5~10 μg/kg,DNSH的线性相关系数为0.999 5,检出限为0.5 μg/kg。在0.5、1.0、2.0和4.0 μg/kg的浓度添加水平下,加标回收率为63.4%~109.5%,RSD为2.0%~11.9%。本方法灵敏度高、重现性好,适用于动物源食品中硝呋索尔代谢物3,5-二硝基水杨酸肼残留量的确证检测。     

液-液萃取/气相色谱-质谱法快速测定酱油中的3-氯-1,2-丙二醇

建立了酱油中3-氯-1,2-丙二醇（3-MCPD）的液-液萃取/气相色谱-质谱联用（LLE/GC-MS）检测方法。丁酮作为提取溶剂同时也是衍生试剂。样品加入同位素内标并用氯化钠饱和后用丁酮进行提取,提取液经干燥和净化后加入对甲苯磺酸作催化剂进行衍生。衍生溶液经中和、干燥后用气相色谱-质谱联用仪在选择离子模式下进行测定。3-MCPD在0.008～2.0μg的含量范围内线性关系良好,相关系数（r）为0.999 9,定量限为0.003 mg/kg。在添加水平0.005～0.40mg/kg时准确度为-8.2%～-1.7%,精密度（RSD）1.3%～3.7%。该方法操作简单,检测成本低且灵敏度高,成本低,选择性好,适用于酱油中的3-氯-1,2-丙二醇的快速测定。     

气相色谱-质谱法测定食品中的3-氯-1,2-丙二醇残留量

本文建立了一个使用GC -ECD和GC MS测定食品中 3 -氯 - 1,2 -丙二醇 (3-MCPD)的方法。本法将试样与Extrelut(经过特殊处理的硅藻土 )拌匀 ,装柱 ,用乙醚取代乙酸乙酯提取 ,经过弗罗里硅土柱净化 ,其中的 3 -MCPD经三氟乙酸酐 (TFAA)在常温下衍生 30min后 ,用配有电子俘获检测器的气相色谱仪和气相色谱质谱联用仪测定。本方法对其净化步骤有很大突破 ,即增加了以弗罗里硅土为层析柱的净化步骤。在Extrelut、弗罗里硅土两次柱净化过程中 ,确定了用一定比例的乙醚 -正己烷预淋洗 ,洗去了大量杂质。用三氟乙酸酐取代了七氟丁酰咪唑 (HFBI)衍生。本法准确、稳定 ,当氯丙醇的添加范围在 0 .0 1- 0 .5 0mg kg时 ,3MCPD的回收率为 80 6 - 117% ,变异系数为 6 5 - 10 1% ,最低检出限为 3μg kg。本方法可适用于肉制品、啤酒、HVP(水解植物蛋白 )、酱油等调味品中的 3 -MCPD的测定     

吡虫啉及其中间体的高效液相色谱法同时测定

研究了用高效液相色谱法同时分离测定农药吡虫啉原粉和中间体2-氯-5-甲基吡啶及2-氯-5-氯甲基吡啶含量的方法。色谱柱为Hypersil ODS2柱,流动相为甲醇：水（48：52）,检测波长为270mm,三个组分均能得到完全分离。方法回收率为99.6%～100.4%,变异系数为2.6%～3.7%,本法简便、快速、准确。为吡虫啉产品质量检测及中间体含量控制提供了可靠的分析方法。     

塑料制品中三（2-氯乙基）磷酸酯含量的测定

采用气相色谱-质谱联用仪,建立了测定塑料制品中三（2-氯乙基）磷酸酯含量的方法。本方法快速准确、灵敏度高,方法的线性范围是2～80mg/L,最低检出限为1mg/kg,回收率大于85%,结果满意。     

利用HPLC-MS/MS联用技术定量测定人血浆中叶酸及5-甲基四氢叶酸浓度的方法学研究

为定量测定人血浆中叶酸及 5 -甲基四氢叶酸浓度 ,建立了利用 HPLC-MS/ MS联用技术的分析方法。血浆样品在弱光环境下 ,经 SPE萃取处理 ,以 5 m mol/ L甲醇与乙酸铵 ( p H6.0 ) ( V(甲醇 ) / V(乙酸铵 ) =2 5∶ 75 )为流动相 ,经 Waters XTerra MS C1 8色谱柱初步分离 ,利用串联质谱多反应离子监测 ( MRM)方式监测叶酸、5 -甲基四氢叶酸和内标的正离子 ,然后进行定量测定。结果表明 :叶酸和 5 -甲基四氢叶酸的最低定量浓度均为 0 .5 ng/ m L;线性范围为 0 .5～ 2 5 ng/ m L,标准曲线相关系数 r≥ 0 .99,精密度和准确度均在± 1 5 %之内。此法专属、灵敏、准确 ,可以用于测定人血浆叶酸和 5 -甲基四氢叶酸的浓度     

毛细管电泳pH碱修饰在线富集方法检测唾液中吗啡类毒品

本文建立了吗啡、可待因和6-单乙酰吗啡的毛细管电泳pH碱修饰在线富集方法,并进行了方法学考察.采用pH 3浓度为100mmol/L的磷酸盐缓冲液(含20％甲醇和5％异丙醇)作为背景缓冲液,0.2psi压力下引入3s含12.5％氨水的甲醇:水(50:50)混合溶液,10kV电压下电迁移进样99s,最后施加25kV电压进行...     

荧光光度法选择性测定水样中痕量镉的研究

本文研究了镉 (Ⅱ ) 8 羟基喹啉 5 磺酸 溴代十六烷基三甲胺体系测定痕量镉的荧光分析方法。Cd(Ⅱ )与 8 羟基喹啉 5 磺酸 (HQS)在强碱性条件下能选择性地形成稳定的配合物 ,发射较强的荧光 ,激发波长和发射波长分别位于 394nm和 5 2 0nm。在溴代十六烷基三甲胺 (CTMAB)表面活性剂存在时 ,络合物的荧光强度显著地增强。在碱性条件下 ,CTMAB浓度为 3× 1 0 3mol/L时 ,镉 (Ⅱ )的浓度在 4 3× 1 0 9～ 6 0× 1 0 6 mol/L范围内线性关系良好 ,检出限为 4 3nmol/L。应用本方法测定生活及环境水样后 ,共加标回收率为1 1 7 1 %～ 1 2 1 8%。本方法操作简便、选择性好、准确度高 ,可直接应用于水样品中镉含量的测定 ,结果令人满意     

Periodic acid-Schiff-phosphotungstic acid as an electron histochemical method for ultrathin sections

Structures which are regarded as ‘PAS positive’ may be strongly and selectively stained for electron microscopy in ultrathin sections by using the following procedure. Tissues were fixed by buffered osmium tetroxide or by glutaraldehyde followed by postfixation in osmium tetroxide. After dehydration the fixed tissues were embedded in butyl methacrylate-methyl methacrylate (10:1 v/v). Other embedding media do not give successful results. Ultrathin sections were cut and mounted on formvar-coated gold grids. The sections were treated with 1% w/v periodic acid in aqueous alcohol (water-ethanol 1:1 v/v) for 10 min, washed in water for 2–3 min, then treated with Schiff reagent for 20 min. The Schiff reagent was made according to the method of de Tomasi and allowed to age for 3–5 h. The sections were then washed in two changes of water for 3–5 min each, dried in air, stained in 1% w/v aqueous phosphotungstic acid for 1.5 h then rinsed in water for 2–3 min.     

铌欠缺对PZN基陶瓷微观结构和介电性能的影响

使用化学混合法制备了PZN基陶瓷 ,研究了铌离子欠缺对其相组成、微观结构和介电性能的影响。随着铌离子欠缺量的增加 ,预烧粉体中的焦绿石相含量大幅度增加 ;但是微量铌离子欠缺对烧结后陶瓷的相组成没有什么影响 ,甚至当铌欠缺量达到 2 %时 ,陶瓷仍然为 10 0 %的钙钛矿结构。随着铌欠缺的增加 ,晶粒尺寸增大 ,但是陶瓷仍具有良好的成瓷性。铌欠缺使介电常数减小 ,但是对介电损耗影响很小 ;介电常数减小的原因归结为“有效有序微区”尺寸的减小和铁电活性的铌离子浓度的降低     

液相色谱-串联质谱法分析大鼠血液中基因组DNA羟甲基化水平

5-羟甲基胞嘧啶（5-hydroxymethylcytosine,5hmC）是由TET蛋白家族催化氧化5-甲基胞嘧啶-（5-methylcytosine,5mC）生成的,对哺乳动物的基因转录和表达发挥着重要的调控作用。本研究建立了血液样品中5hmC的液相色谱-串联质谱（LC-MS/MS）测定方法,采用试剂盒法提取血液基因组DNA,在甲酸环境下加热裂解,采用HILIC色谱柱分离,电喷雾电离和多反应监测模式定量。结果表明：5hmC在0.1~50 μg/L范围内线性关系良好,相关系数为0.999 4;高、中、低3个加标水平的平均回收率为95.87%,日内和日间的相对标准偏差分别为3.42%和4.12%;5hmC的检出限（LOD,S/N=3）为0.050 μg/L,定量限（LOQ,S/N=10）为0.100 μg/L。该方法准确、快速、稳定、灵敏,可用于血液样品全基因组中5-羟甲基胞嘧啶的检测分析。     

Comparison of 5-Axis and 3-Axis Finish Machining of Hydroforming Die Inserts

The recent growth in hydroforming technology has sparked interest in alternative methods to the current conventional die manufacturing techniques. Hydroforming dies typically have shallow forming channels and open, low curvature surfaces, making them ideally suited for 5-axis machining. To fully appreciate the benefits and to properly demonstrate the capabilities of 5-axis machining for hydroforming dies, a comparison of 5-axis and 3-axis finish machining was done. Two hydroforming die insert sets were machined on a 5-axis machine with a tilt/rotary table. The tool paths for 5-axis machining were generated using custom software based on a modified form of a tool positioning strategy called the principal axis method. The quality of generated 3-axis toolpaths was verified against the machining times of a third set of die inserts, similar to those machined in 5-axis, by an independent industrial mould and die manufacturer using a 3-axis high-speed machine. A comparison of the generated 3-axis paths versus the 5-axis paths for one of the die inserts was made using total finish machining tool path lengths to eliminate differences in machines. The results show that the generated 3-axis tool paths are longer than the 5-axis paths by at least 247%. The paper discusses the different tool-path generation methods along with the geometry of cusp formation and the effect of tool selection. Methods to improve the 3-axis results are also presented.     

RP—HPLC法测定鼠肝组织儿茶酚氧位甲基转移酶活性的研究

建立了反相液相色谱法测定鼠肝组织儿茶酚氧位甲基转移酶（COMT）活性的方法。以3,4-二羟基苯甲酸为底物,测定产物4-羟基-3-甲氧基苯甲酸的生成量计算酶活。色谱柱AgilentZORBAXEclipseXDB—C18（150×4．6mm,5iμmd）,流动相为甲醇／0．7％乙酸水溶液（23／77,v／v）,流速1．0mL／min,检测波长254nm,柱温25％。4-羟基-3-甲氧基苯甲酸的线性范围0．5～20μg／mL,回收率94—98％,RSD小于5％,检测限0．1μg/mL（S／N=3）。结果表明,该方法简便、快速、重复性好,可应用于鼠肝组织中COMT活性的测定。     

SURFACTANT MEDIATED EXTRACTION OF TRITERPENES AND THEIR DIRECT HPLC ANALYSIS FROM THE MICELLAR SYSTEM

The pentacyclic triterpenes oleanolic acid (OA) and ursolic acid (UA) in Salvia triloba are attractive ingredients for cosmetic and pharmaceutical formulations. These triterpenoids are constitution isomers and differ only in the position of one methyl group in their chemical structures. Therefore it is difficult to achieve a baseline separation by standard RP-HPLC systems. Another challenge is that the complex plant contains a large variety of similar compounds. To achieve precise results for the target molecules, these compounds should be removed prior to analysis. Due to the large application of these two triterpenes, a fast quantification method is favored. If the triterpenes are extracted with aqueous two-phase systems, the target substances are enriched in a surfactant-rich phase. For this application, it is desirable to develop a method that is capable of quantifying both triterpenes directly by RP-HPLC without additional purification steps.

The optimal chromatographic conditions for pure substances as well as for crude surfactant-containing extracts were accomplished on a Nucleodur C18 ISIS column by isocratic elution with methanol/water/acetic acid/triethanolamine (90:10:0.04:0.02 v/v) as the mobile phase and a column temperature of 10°C. The flow rate was 0.6 mL/min, and the detection wavelength was 210 nm. With these parameters, a baseline separation was achieved and the calibration curve showed a very good linearity (R² > 0.999 for OA and UA) within the test range. The method is simple, rapid, and reliable for the quantification of crude extracts from plant material.