HPLC—ELSD法快速测定甲基葡萄糖苷的含量

建立了高效液相色谱—蒸发光检测器(HPLC—ELSD)法检测甲基葡萄糖苷含量的方法。最佳色谱分析条件为:Alltech Apollo C18色谱柱(4.6 mm×250 mm,5μm),流动相V(水)∶V(甲醇)=5∶95,流速为0.7 m L/min,柱温为30℃。ELSD检测器漂移管温度为104℃,载气(空气)流速为2.8 L/min。甲基葡萄糖苷在2.5~12.5μg/μL之间具有良好的线性关系,r=0.999 1,回收率为100.0%~106.3%。该方法简便易行,分析速度快,具有良好的重复性和精密度,适合用于甲基葡萄糖苷的检测。     

HPLC-MS/MS法检测2-氯-2-脱氧-D-葡萄糖方法优化及验证

建立了高效液相色谱-三重四极杆串联质谱(HPLC-MS/MS)检测2-氯-2-脱氧-D-葡萄糖(ClDG)的分析方法。采用多反应监测(MRM)负离子电喷雾模式进行HPLC-MS/MS分析。色谱柱为:Alltima Amino 100A 5μm柱(250 mm×4.6 mm),流动相为:V(5 mmol/L乙酸铵)∶V(乙腈)=10∶90;柱温:35℃;流速:1 mL/min;进样量:5μL。ClDG浓度在0.5~37.5μg/m L范围内与峰面积有良好的线性关系,检出限为0.15μg/mL,定量限为0.5μg/mL,方法回收率为92.6%~105.1%。该方法选择性、重复性良好,灵敏度高,能用于ClDG的痕量分析。     

一种高哌嗪溴盐的液相分析新方法

建立了一种高效液相色谱法测定高哌嗪溴盐的新方法,确定了最优的色谱条件,色谱柱采用岛津VP-ODS色谱柱,柱长为250 mm,内径为4.6 mm;流动性采用V(甲醇)∶V(水)=10∶90(水相含30 mmol/L磷酸二氢钾,稀酸调p H=3.5);检测波长为220 nm;流速为1.0 m L/min;进样量为2.0μL。该分析方法填补了国内空白,分离度R≥1.5,线性相关系数达到了0.999以上,标准偏差均小于1.4%,加标回收率在98%~103%之间。实验结果表明,该方法能够满足工艺中控分析的需要。     

HPLC-MS/MS测定化妆品中5种禁用胆碱类化合物

建立了高效液相色谱-质谱/质谱(HPLC-MS/MS)测定化妆品中5种禁用胆碱类化合物的分析方法。样品经甲醇-水(V(甲醇)∶V(水)=3∶1)溶液涡旋振荡、超声辅助液分散提取,离心后经Welch Ultimate XB-C_(18)(4.6 mm×150 mm,5μm)色谱柱分离。通过质谱电喷雾正离子模式(ESI+)电离、多反应监测模式(MRM)测定。在最优化条件下,5种禁用胆碱类化合物均获得良好分离,峰形对称性好。水杨酸胆碱在10.0~80.0μg/L范围内线性良好,相关系数为0.999 1,其他胆碱在1.0~40.0μg/L范围内线性良好,相关系数大于0.995 0;方法检出限和定量限分别在2.0~30.0μg/kg和6.0~90.0μg/kg之间。添加回收实验结果表明,5种胆碱类化合物的回收率在85.4%~103.9%之间,日内精密度为1.9%~6.9%(n=6)。     

高效液相色谱法测定化妆品中的二羟基丙酮

建立了测定化妆品中二羟基丙酮的高效液相色谱检测方法。采用资生堂PC HILIC色谱柱(4.6 mm×250 mm,5μm),流动相V(乙腈)∶V(5 mmol/L乙酸铵溶液)=92∶8,流速1.0 m L/min,检测波长272 nm,乙腈(体积分数为80%)为溶剂,超声提取样品。结果表明,在此条件下,二羟基丙酮在0.1~1.0 g/L内线性关系良好(r=0.999 8),回收率为92.7%~99.9%,相对标准偏差(RSD)为0.55%~1.96%。该方法快捷、简便、准确,可用于测定化妆品中的二羟基丙酮。     

反相高效液相色谱-激光诱导荧光法检测饮料中的维生素B_2

在Sinochrom ODS-BP(5μm,4.6 mm×200 mm)色谱柱上,以甲醇-乙酸钠溶液为流动相,采用LIFD230激光诱导荧光检测器,建立了一种对饮料中维生素B2进行检测的反相高效液相色谱-激光诱导荧光检测方法。考察了样品处理方法、流动相配比及流动相pH对检测结果的影响。对检测条件进行了优化,在柱温为室温、流速为1 mL/min、V(甲醇)∶V(0.01 mol/L乙酸钠溶液)为1∶1及pH为5.0的条件下,维生素B2的线性范围为0.05~5μg/mL,样品加标回收率为96.52%~99.03%,RSD为3.25%,检出限为9.4×10-4μg/mL。该方法具有灵敏度高、检出限低及响应快等特点。     

高效液相色谱法测定工业废水中盐酸苯肼

通过实验建立了工业废水中盐酸苯肼的高效液相色谱分析方法。色谱条件为:Kromasil-C18(150 mm×4.6 mm,5μm)色谱柱,流速1 mL/min,柱温30℃,进样体积10μL,流动相为V(甲醇)∶V(8 mmol/L KH2PO4+4 mmol/LK2HPO4)=35∶65,测定波长235 nm。测定结果表明,线性范围为0.1～100 mg/L,平均加标回收率为98.2%,相对标准偏差为1.06%。该方法操作简单,分析快速、准确。     

螯合剂EDDS中[S,S]-EDDS与[R,S]-EDDS的液相色谱法测定

建立了螯合剂乙二胺二琥珀酸(EDDS)的2种异构体[S,S]-EDDS与[R,S]-EDDS的液相色谱测定方法。采用DAD检测器,ODS C_(18)色谱柱(4.6 mm×250 mm,5μm),柱温30℃,流动相为V(6 mmol/L醋酸铜缓冲液)∶V(甲醇)=90∶10,流速1.0mL/min,254nn波长下检测。结果显示,[S,S]-EDDS与[R,S]-EDDS分别在20μg/mL~210μg/mL和6μg/mL~60μg/mL有良好的线性关系,相关系数均0.999,相对标准偏差RSD1%,回收率在95%~105%。此方法准确、可靠,可用于EDDS中[S,S]-EDDS与[R,S]-EDDS的分析测定。     

高效液相色谱法测定化妆品中的苯氧异丙醇

以超声辅助提取法对不同基质类型的化妆品样品进行预处理,采用高效液相色谱法测定化妆品中的苯氧异丙醇,色谱条件为:Kromasil C18色谱柱(250 mm×4.6 mm i.d.,5μm),流动相为V(水)∶V(乙腈)∶V(甲醇)∶V(四氢呋喃)=60∶25∶10∶5的混合溶液,流速1.2 mL/min,检测波长268 nm,柱温30℃。结果表明,在此条件下苯氧异丙醇在1.0~200.0μg/mL范围内与相应的峰面积具有良好的线性关系(相关系数r=0.999 9),线性回归方程为A=74 280ρ-23 780,回收率为95.6%~102.4%,RSD为0.66%~1.05%。     

高效液相色谱法测定化妆品中熊果酸的含量

采用甲醇超声提取,液相色谱分离的方法测定化妆品中熊果酸的含量。色谱条件为:Agilent HC-C18(250 mm×4.6 mm,5μm)色谱柱,流动相V(甲醇)∶V(水)∶V(冰乙酸)=87∶13∶0.03,流速1.0 mL/min,紫外检测波长215 nm。结果表明,在此条件下熊果酸在0.2μg/mL~103μg/mL与相应的峰面积具有良好的线性关系(r>0.999 7),线性回归方程为y=25.367 5x 0.546 9,回收率在96.4%~101.3%,方法精密度RSD<3.6%。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。