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%。     

RP-HPLC法测定不同产地延胡索中延胡索乙素含量

用RP-HPLC法测定了对不同产地延胡索中延胡索乙素的含量。测定使用Kromasil C18色谱柱(200 mm×4.6 mm,5μm),以甲醇-0.1%磷酸溶液(用三乙胺调至pH 6.09)(V∶V,55∶45)为流动相,流速为1.0 mL/min,检测波长为280 nm。该方法的线性范围是22.0~352.0μg/mL,平均回收率98.6%,RSD=0.4%(n=9)。该法可用于质量控制。     

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。     

土壤中氨基甲酸酯类农药检测的方法优化

为高效准确地测定土壤中10种氨基甲酸酯类农药，研究建立一种适用于土壤中10种氨基甲酸酯类农药含量的柱后衍生-液相色谱快速检测方法。试验优化提取条件、固相萃取柱和色谱条件，结果表明：水浴温度35℃,提取液为V(甲醇)∶V(二氯甲烷)=1∶1,提取体积为50 mL、超声时间25 min,采用Carb/NH₂固相萃取柱净化，选择Shim-pack FC-ODS(75 mm×4.6 mm, 3μm)液相色谱柱分析测试。本检测方法的线性系数均可达到0.999 3以上；线性范围为0.02～10μg/mL;检出限均小于2.0μg/kg;对10.0 g左右的土壤进行低(5μg/kg)、中(50μg/kg)、高(500μg/kg)三个浓度水平的加标测试时，10种氨基甲酸酯类农药的加标回收率为75.7%～118.5%;重现性良好，相对标准偏差为0.8%～6.8%;该方法能够满足测定土壤中10种氨基甲酸酯类农药的需要。     

高效液相色谱法测定一种新型抗高血压原料药的含量

原料药的含量测定是新药研发的关键步骤。依据新药注册标准，建立了一种新型抗高血压原料药含量检测的高效液相色谱方法。按照《药典》(2020版)指导原则，优化色谱条件，并进行方法学验证，将其用于不同批次原料药的含量检测。结果显示，最佳色谱条件为Aligent TC-C₁₈色谱柱(250 mm×4.6 mm, 5μm),V(甲酸)∶V(甲醇)=20∶80[φ(甲酸)=0.2%]等度洗脱，流速1.0 mL/min,柱温30℃,检测波长280 nm。该方法系统适用性强，重复性好，专属性高，t<48 h对照溶液性质稳定；线性范围为1.5～2 000μg/mL,线性方程为y=3.224 4x-2.435 3(r=0.999 9),检测限为0.5μg/mL,回收率为99.3%～104.5%。该方法为该原料药的质量监控提供了可靠的保障。     

高效液相色谱法测定熊果酸-乙醇共晶中熊果酸的含量

目的建立高效液相色谱法测定熊果酸-乙醇共晶中熊果酸的含量分析方法。方法以Sino Pak-C18(4.6 mm×250 mm,5.0μm)为色谱柱,甲醇∶0.1%磷酸水(v∶v(88∶12))为流动相,流速为1.0 m L/min,进样量为20μL,在210 nm波长处测定检测其含量。结果熊果酸在浓度80.0~120.0μg/m L范围内线性关系良好;准确度、精密度、稳定性试验的RSD均小于2.0%。结论该方法操作简便,结果重现性好,准确快速,适用于熊果酸含量的测定。     

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。     

高效液相色谱法定量检测化妆品中着色剂颜料红49

建立了化妆品中限用有机合成着色剂颜料红49的高效液相色谱/二极管阵列检测器检测方法.色谱柱采用C18反相柱(250 mm×4.6 mm,5μm),流动相为V(10 mmol/L的四甲基氢氧化铵水溶液(醋酸调pH =7))∶V(甲醇)=30∶70的混合溶液,等度洗脱,检测波长为494 nm,柱温30℃,流速1.0 mL/min,以保留时间定性,外标法定量.结果表明,在此条件下颜料红49在1 ～ 600 μg/mL范围内与其相应的峰面积呈良好的线性关系,检出限为0.2μg/mL,回收率为90.94％ ～ 101.05％.     

反相高效液相色谱法测定化妆品中巯基乙酸

采用反相高效液相色谱法测定化妆品中巯基乙酸的含量。色谱条件为:Kromasil C18(250 mm×4.6 mm,5μm)色谱柱,流动相为V(乙腈)∶V(0.01 mol/L KH2PO4溶液(磷酸调pH=2.5))=10∶90的混合溶液,流速1.0 mL/min,检测波长215 nm,柱温30℃,进样量20μL。结果表明,此条件下巯基乙酸在5.0～150.0μg/mL质量浓度范围内与峰面积线性良好,线性回归方程为Y=5 100X-13 400(r=0.999 8),平均回收率在98.4%～100.8%,RSD为0.09%～0.84%。     

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.     

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.