高效液相色谱法测定化妆品中氨甲环酸的含量

建立了测定化妆品中氨甲环酸含量的高效液相色谱法。采用Zorbax SB C_(18)色谱柱(250 mm×4.6 mm,5μm)分离,以水-甲醇-18.3 g/L磷酸二氢钠溶液(含体积分数1.26%的三乙胺,pH=2.5)为流动相进行梯度洗脱,流速0.8 m L/min,柱温25℃,进样量10μL,样品经体积比为1∶1的甲醇-饱和氯化钠溶液提取,用二极管阵列检测器(DAD)检测,检测波长220 nm,外标法定量。结果表明,氨甲环酸在100~4 000 mg/L范围内线性关系良好,相关系数R~2=0.999 9。方法的检出限为7 mg/L,定量限为22 mg/L。样品的平均加标回收率为94.0%~102.5%,相对标准偏差为0.57%~2.69%(n=3)。该方法前处理简单、回收率高、精密度好,适用于化妆品中氨甲环酸含量的测定。     

化妆品中贝美格及其盐类的高效液相色谱检测及质谱确证

研究建立了化妆品中贝美格及其盐类的高效液相色谱分析方法及质谱确证方法。化妆品样品以甲醇为提取溶剂进行超声提取,提取液离心处理,取上清液经微孔滤膜过滤后测定。采用Symmetry C_(18)(4.6 mm×250 mm, 5μm)高效液相色谱柱进行分离测定,外标法定量。化妆品中贝美格及其盐类的方法定量限均为0.5 mg/kg,在低、中、高3个添加水平范围内平均回收率为85.1%～107.4%,相对标准偏差为3.7%～9.3%。对于疑似阳性样品,进一步采用高效液相色谱-串联质谱法进行确认分析。     

柱前衍生-高效液相色谱法测定化妆品中游离甲醛

采用柱前衍生-高效液相色谱法测定化妆品中的游离甲醛。根据样品基质类型及配方的不同,采用两种方法进行提取。样品中的游离甲醛与五氟苯肼快速反应后,用有机溶剂萃取转移,经高效液相色谱测定,外标法进行定量,阳性样品用高效液相色谱-三重四级杆串联质谱进行确证。采用INERTSIL ODS-SP色谱柱(25 cm×0.46 cm×5μm),流动相A为甲醇,流动相B为体积分数0.2%的磷酸水溶液,流速1.0 m L/min,检测波长为255 nm,柱温40℃。方法在50~2 000μg/g的质量比范围内线性关系良好,相关系数(r)0.999。平均加样回收率为87.2%~108.2%,最低检出质量比为30μg/g。该方法快速简便,可用于化妆品中游离甲醛的定量分析。     

液相色谱-串联质谱法测定化妆品中多种激素

采用液相色谱-串联质谱法测定化妆品中糖皮质激素、雌激素、雄激素、孕激素等激素的含量。不同形态的化妆品样品以甲醇为提取剂进行超声提取,样品提取液离心后得到上清液经HLB固相萃取小柱净化,用Agilent ZORBAXEclipse XDB-C18柱(1.8μm,2.1 mm×50 mm),乙腈-水作为流动相,梯度洗脱,流速0.3 mL/min,柱温25℃,进样量2.0μL,糖皮质激素、雄激素、孕激素采用正离子扫描模式,雌激素采用负离子扫描模式,多反应监测测定。化妆品样品平均加标回收率为72.31%~97.89%,相对标准偏差为2.24%~11.34%,方法检出限为0.002 mg/kg~0.8 mg/kg。     

高效液相色谱法测定化妆品中22种紫外吸收剂

建立了一种高效液相色谱同时测定防晒类化妆品中22种紫外吸收剂的方法。以四氢呋喃或V(四氢呋喃)∶V(水)∶V(甲醇)=9∶6∶5的混合溶液提取化妆品中的紫外吸收剂,以Agilent C_(18)色谱柱进行分离,以甲醇-高氯酸水溶液-四氢呋喃-乙腈混合液为流动相进行梯度洗脱,流速1.0 m L/min,在检测波长311 nm处进行测定。结果表明,22种紫外吸收剂的色谱峰实现良好分离,线性范围为0.1~500 mg/L,相关系数均大于0.999,定量限均不高于4.6 mg/L,加标回收率为85.6%~101.0%。建立的方法线性范围宽、定量限低、灵敏度高、结果准确可靠,能够满足《化妆品安全技术规范》(2015年版)对紫外吸收剂的检测要求。     

液相色谱法测定美白类化妆品中的阿魏酸、苯乙基间苯二酚、辛酰水杨酸

建立了液相色谱测定美白类化妆品中阿魏酸、苯乙基间苯二酚、辛酰水杨酸含量的方法.样品经过甲醇超声提取后,用Aglient Extend-C18色谱柱(4.6 mm×250 mm×5μm)分离,以乙腈-5 mmol/L癸烷磺酸钠(含质量分数0.1％磷酸)作为流动相梯度洗脱,PDA检测器检测.阿魏酸、苯乙基间苯二酚、辛酰水杨...     

液相色谱-串联质谱法测定化妆品中新型防腐剂月桂酰精氨酸乙酯盐酸盐

建立了液相色谱-串联质谱法测定化妆品中防腐剂月桂酰精氨酸乙酯盐酸盐(ethyl lauroyl arginate hydrochloride,以下简称LAE)的分析方法。采用超声波溶剂提取法提取样品中的LAE,经筛选确定使用Waters ACQUITY UPLC~? BEH C_(18)(2.1 mm×100 mm×1.7μm)色谱柱,流动相为质量分数0.1%甲酸水溶液和乙腈,梯度洗脱,然后用质谱法检测,以外标法定量。最佳提取条件为:提取溶剂甲醇,提取时间20 min,提取次数3次。LAE的线性范围为0.5～10 ng/m L,线性相关系数为0.9990。方法的检出限为1μg/kg,定量限为10μg/kg;通过加标回收率试验,确定方法的加标回收率范围为84.9%~110.0%。该方法简单、便捷,适用于化妆品中LAE含量的测定。     

高效液相色谱法同时测定化妆品中12种美白成分

采用高效液相色谱法(HPLC)同时测定化妆品12种美白成分。样品经质量分数50%甲醇溶液提取、过滤后,进行HPLC分析。色谱柱为Phenomenex Luna C18(2)柱(4.6 mm×250 mm×5μm)。流动相组成为甲醇-0.02 mol/L KH2PO4溶液,梯度洗脱。流速为1.0 m L/min。二极管阵列检测器,L-抗坏血酸-2-磷酸酯镁、鞣花酸及甘草酸二钾的检测波长为254 nm,烟酸、曲酸、氢醌、烟酰胺、树莓苷、4-甲氧基水杨酸钾、苯酚、杜鹃醇和苯乙基间苯二酚的检测波长为220 nm。结果发现,12种美白类成分均在0.5~50μg/m L范围内线性关系良好(相关系数r0.999),霜类、乳液类、水剂类3种化妆品基质中12种美白成分的回收率(添加水平分别为20、50和200μg/g)在85.6%~111.9%之间,相对标准偏差(RSD)在0.4%~8.9%范围内,最低检出质量比在0.3~1.5μg/g之间。     

高效液相色谱法测定化妆品中烟酰胺的含量

建立了一种测定化妆品中烟酰胺的高效液相色谱方法。试验以质量分数0.1%甲酸水溶液-甲醇(体积比95∶5)为流动相,用C18色谱柱分离,流速为1.0mL/min,检测波长260nm,检测化妆品中的烟酰胺。结果显示烟酰胺线性范围为0.5~20mg/L,化妆品中定性检出限为0.50mg/kg,平均回收率为91.3%~109.4%。此方法样品处理简单,分析准确可靠,适用于对各类化妆水和护肤霜中烟酰胺的检测。同时对于阳性样品,建立了液相色谱-串联质谱的确证方法。     

高效液相色谱法测定化妆品中的氨甲环酸

建立了美白类化妆品中氨甲环酸的高效液相色谱测定方法。采用5%甲醇溶液对化妆品样品中的氨甲环酸进行提取。样品用Shiseido CAPCELL PAK C_(18) UG120色谱柱(4.6 mm×250 mm,5μm)分离,以甲醇与0.05 mol/L KH_2PO_4-0.2%H_3PO_4溶液(体积比为5∶95)为流动相,流速为1.0 mL/min,检测波长为210 nm。结果表明,氨甲环酸在5～100 mg/L范围内线性关系良好,相关系数(r)大于0.999。在各化妆品基质中方法检出限为10.7～22.2μg/g,方法定量限为28.9～48.0μg/g。回收率为95.23%～110.40%,RSD值为1.24%～3.59%(n=6)。日内稳定性良好,在24 h内峰面积RSD值为0.026%。该方法简便、可靠,可作为美白类化妆品中氨甲环酸的含量测定方法。     

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.     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006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生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。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（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008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、不饱和聚酯树脂、环氧树脂)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.