固相萃取——高效液相色谱法分离红花中的黄酮类物质

目的 研究红花中的黄酮类物质。方法 乙醇浸泡提取，固相萃取分离，液相色谱法进行纯度检测，结果 采用的红花中有两种黄酮类物质。结论 洗脱液V（H2O）：V（C4H5OH）=3：7，能很好的分离红花中的两种黄酮类物质。     

Chemical Synthesis and Structure-Activity Relationship Study Yield Desotamide a Analogues with Improved Antibacterial Activity

Desotamides A, a cyclohexapeptide produced by the deep-sea-derived Streptomyces scopuliridis SCSIO ZJ46, displays notable antibacterial activities against strains of Streptococcus pnuemoniae, Staphylococcus aureus, and methicillin-resistant Staphylococcus epidermidis (MRSE). In this study, to further explore its antibacterial potential and reveal the antibacterial structure-activity relationship of desotamides, 13 cyclopeptides including 10 new synthetic desotamide A analogues and wollamides B/B1/B2 were synthesized and evaluated for their antibacterial activities against a panel of Gram-positive and -negative pathogens. The bioactivity data reveal that residues at position II and VI greatly impact antibacterial activity. The most potent antibacterial analogues are desotamide A4 (13) and A6 (15) where l-allo-Ile at position II was substituted with l-Ile and Gly at position VI was simultaneously replaced by d-Lys or d-Arg; desotamides A4 (13) and A6 (15) showed a 2–4-fold increase of antibacterial activities against a series of Gram-positive pathogens including the prevalent clinical drug-resistant pathogen methicillin-resistant Staphylococcus aureus (MRSA) with MIC values of 8–32 μg/mL compared to the original desotamide A. The enhanced antibacterial activity, broad antibacterial spectrum of desotamides A4 and A6 highlighted their potential as new antibiotic leads for further development.     

结香鲜花香气化学成分的研究

采用固相微萃取(SPME)吸附采集结香(Edgeworthia chrysantha Lindl.)鲜花的香气成分，用色谱-质谱联用分析鉴定，并用GC-MS总离子流色谱峰的峰面积进行归一化定量分析结香鲜花的香气成分，鉴定出γ-萜品烯56．41％、乙酸苄酯10．77％、β-苯乙基乙酸酯9．58％、3，7-二甲基-2，6-辛二烯-1-醇乙酯5．61％、水杨酸甲酯3．91％、苯甲酸甲酯2．85％、反式罗勒烯1．80％、苯甲醛1．75％和3-甲基-3-癸烯-2-酮1．40％等30种化合物。固相微萃取-气相色谱-质谱法是一种可用于鲜花香气成分分析的简单可行的分析方法。     

鹿角杜鹃开花过程中挥发性成分的变化

利用顶空固相微萃取-气相色谱质谱法,对鹿角杜鹃Rhododendron latoucheae花朵在花蕾期、半开放期、盛开期及凋落期4个开花期的挥发性成分进行了定性和相对定量分析,研究了鹿角杜鹃花香成分的种类和变化情况.结果表明,在鹿角杜鹃花朵开放的4个时期中共检测出37种挥发性成分,这些挥发性成分种类在开花过程中呈升高...     

固相萃取-高效液相色谱法测定生姜中涕灭威及其代谢物

建立了生姜中涕灭威、涕灭威砜和涕灭威亚砜残留量检测的固相萃取—高效液相色谱分析方法。样本采用乙腈提取,经C18固相萃取柱净化,浓缩定容后用HPLC-FLD检测分析,外标法定量。结果表明:该方法在0.02~8.0 mg/L标准曲线线性良好,相关系数均达到0.999以上,样本添加水平为2.0×10-2、4.0×10-2mg/kg时,回收率为80.25%~102.85%,相对标准偏差为3.64%~8.67%,方法检出限均低于2.5×10-3mg/kg。该方法具有准确度高及净化效果好等特点,能很好地满足实际样本残留分析要求。     

金银花和红银花挥发性成分的顶空固相微萃取#br# 气质联用检测与比较

 采用顶空固相微萃取气质联用（SPME–GC–MS）的方法检测红银花与金银花新鲜花蕾和 干花蕾的挥发性成分。4 种花蕾样品共鉴定出67 种挥发性物质,其中新鲜红银花与金银花分别检测出48 种和46 种,经烘干处理的干红银花与金银花分别检测出34 种和37 种。[3.2.1.0（1,5）]三环辛烷、β– 芳樟醇、5–甲基–2–己醇和以及十六烷是4 种样品共有的成分。其中红银花挥发性成分主要以烃类、 醇酮类为主,β–芳樟醇含量显著高于金银花;样品在由新鲜到烘干这一过程中,烃类和酯类挥发性物质 含量降低,醛类和醇酮类挥发性物质显著增加。     

Interference elimination of PCB and its ramification in determining trace PBBs/PBDEs by GC/MS

The normal method to determine the trace brominated flame retardants such as polybrominated biphenyls (PBBs) and polybrominated diphenylethers (PBDEs) contained in the electronic and electrical products is gas chromatography/mass spectrometry (GC/MS). However, the method is based on the determinations of the persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs), and polychlorinated naphthalene (PCNs) etc. The interferences of those compounds are inevitable. Therefore, in order to overcome this problem, two methods e.g. 1) The combination use of gas chromatography negative ion chemical ionization mass spectrometry (GC-NICI-MS) and gas chromatography-electron impact-mass spectrometry (GC-EI-MS) is employed, 2) a matrix solid-phase dispersion (MSPD) method with YMC ODS-C18 as carrier is developed. The result show that, by the former method, the brominated isomers or ramifications are distinguished remarkably from other halogen compounds because that anion fragment retention peaks of ［Br］-, ［HBr2］- and molecule chain fragment retention peaks of ［M+2］+,［M+4］+,［M+6］+,［M+8］+ are observed simultaneously, and thus the selectivity to determine bromine-containing retardant flames is greatly improved. Using the latter method, the gas chromatographic peaks of multiple polychlorinated biphenyls and polybrominated diphenylethers can be efficiently separated. Thus provides a project to solve interferences of POPs in brominated flame retardants’ determinations. The standard addition experimental results of 10 kinds of BDEs/PCBs belonging to 8 sorts of electronic and electrical equipment show this method has a high precision and reliability due to 60%～98% recovery and <9.5% relative error, which meet the needs regulated by the IEC Commission. It provides a technical support for electronic and eletrical industries in China to further comply with RoHS directive.     

紫丁香鲜花香气化学成分的研究

采用固相微萃取吸附采集紫丁香Syringa oblata鲜花的香气成分,用色谱/质谱联用分析鉴定,并用GC/MS总离子流色谱峰的峰面积归一化法对紫丁香鲜花的挥发性成分进行定量分析。结果鉴定出大香叶烯-D(22.37%)、β-波旁烯(15.97%)、苯甲醛(11.03%)、β-石竹烯(7.56%)、β-古芹烯(3.43%)、芳樟醇(3.18%)、丁香醛B(2.99%)、α-胡椒烯(2.70%)、β-苯乙醇(2.39%)、苯乙醛(1.99%)、苯甲醇(1.89%)、丁香醇B(1.87%)、α-愈创木烯(1.49%)、丁香醛A(1.46%)、α-蒎烯(1.39%)、丁香醇A(1.03%)、α-草烯(1.03%)等48种化合物。其中所含的4个丁香醇异构体和2个丁香醛异构体是紫丁香鲜花的特征香气成分。固相微萃取-气相色谱/质谱法是一种可用于鲜花挥发性香气成分分析的简单可行的分析方法。图1表1参10     

固相萃取——气相色谱法测定蔬菜中多种有机磷农药的残留量

建立了固相萃取气相色谱法测定蔬菜中多种有机磷农药残留量的方法.蔬菜样品采用乙腈提取,氯化钠盐析分层,取部分提取液使用氮气吹干,以丙酮溶解,固相萃取柱进行净化,最后用气相色谱法进行定量分析,外标法定量.3个添加水平的12种有机磷农药平均回收率(n=5)为75.1%-105.0%,相对标准偏差为1.67%-7.50%.此方法具有快速、简便、准确、灵敏、重现性好的特点,适合蔬菜中有机磷农药残留量的测定.     

Comparison of Headspace Solid-Phase Microextraction with Simultaneous Steam Distillation Extraction for the Analysis of the Volatile Constituents in Chinese Apricot

Volatile constituents in fully mature fruits of apricot （Prunus armeniaca L.） cultivar Xinshiji were extracted using headspace solid-phase microextraction （HS-SPME） and simultaneous steam distillation extraction （SSDE） and then analyzed using capillary gas chromatography and gas chromatography-mass spectrometry. A total of 70 components were identified by HSSPME, including 20 esters, 19 hydrocarbons, 5 alcohols, 5 ketones, 4 acids, 4 lactones, 3 aldehydes, and 10 miscellaneous components, with the esters being the dominant constituent. On the basis of the odor unit values, it is believed that the following compounds probably contributed to the fresh apricot odor： hexyl acetate, β-ionone, butyl acetate, （E）-2-hexenal, linalool, limonene, γ-decalactone, and hexanal. A total of 49 components were also detected by SSDE, including 13 hydrocarbons, 9 alcohols, 7 aldehydes, 9 esters, 4 ketones, 4 lactones, 2 acids, and 1 miscellaneous component, of which the monoterpene alcohols were the dominant constituents. It could be judged from the odor unit values that the following compounds were the major contributors to boiled apricot aroma： β-ionone, linalool, hexyl acetate, γ-dodecalactone, γ- decalactone, （E）-2-hexenal, hexanal, γ-octalactone, phenylacetaldehyde, butyl acetate, limonene, α-terpineol, and δ-decalactone. The results show that HS-SPME is a simple, rapid, and solvent-free method, which is an alternative to the classical SSDE.