液相色谱串联质谱法快速测定猪尿中10种镇静剂类药物残留量

建立了快速测定猪尿中10种镇静剂类药物(噻拉嗪、阿扎哌隆、氟哌啶、氟哌啶醇、艾司唑仑、硝西泮、地西泮、奥沙西泮、氯丙嗪和奋乃静)残留量的液相色谱串联质谱方法.猪尿样品离心后过C18固相萃取小柱,用甲醇-乙酸乙酯(1∶ 4, V/V)混合溶剂洗脱,氮气吹干后用0.1%甲酸溶液溶解进行仪器分析.采用Eclipse XDB-C18色谱柱分离,以乙腈和0.1%甲酸溶液为流动相进行梯度洗脱,电喷雾正电子(ESI+)模式电离,多反应监测(MRM)模式检测,基质校准进行定量分析.10种镇静剂类药物在5～200 μg/L范围内呈良好的线性,线性相关系数均大于0.99.方法检出限为0.11～0.52 μg/L; 定量限为0.20～0.91 μg/L.添加浓度为1.0, 2.0和10.0 μg/L时,平均回收率在74.6%～115 %之间,批内和批间相对标准偏差均小于15%.     

液相色谱-串联质谱法检测蜂蜜中杀虫脒及其代谢产物残留

建立了液相色谱-串联质谱分析洋槐蜜、荆条蜜、蜂巢蜜、杂花蜜、野蜂蜜中杀虫脒及其代谢产物残留的方法。样品经氢氧化钠水溶液稀释溶解后,采用Waters Oasis HLB固相萃取柱净化。样品提取液经Agilent XDB-C18色谱柱分离,以0.1%甲酸水溶液和乙腈为流动相进行梯度洗脱。以电喷雾正离子(ESI+)模式电离,多反应监测(MRM)模式检测,基质匹配标准溶液外标法定量。杀虫脒及其代谢产物(4-氯邻甲苯胺)在2.5～250 μg/L范围内呈线性相关,相关系数(r)均大于0.999;定量限(S/N＞10)为5 μg/kg,检出限(S/N＞3)为2.5 μg/kg。各种蜂蜜基质样品在5、10和20 μg/kg添加水平时,杀虫脒及其代谢产物的回收率范围分别为75.8%～113.8%和85.6%～114.3%,相对标准偏差(RSD)分别为4.8%～10.2%和4.7%～9.1%,可以满足蜂蜜中杀虫脒及其代谢产物残留量的检测需要。     

蜂产品中9种硝基咪唑类药物原药及代谢物残留量的HPLC-APCI(+)MS/MS分析

运用高效液相色谱-大气压电离串联四极杆质谱(HPLC-APCI(+)MS/MS)内标法分析了蜂蜜、蜂王浆及冻干粉中甲硝唑、地美硝唑(二甲硝唑)、替硝唑、洛硝唑(罗硝唑)、特尼哒唑、异丙硝唑,以及羟基化甲硝咪唑、羟基化异丙硝唑、2-羟甲基-1-甲基化-5-硝咪唑9种硝基咪唑类药物残留量.样品添加氘代标示物HMMNI-D3、IPZ-OH-D3后,用乙腈提取,通过Oasis MCX C18 SPE柱净化,Waters Superiorex ODS C18色谱柱分离,采用梯度洗脱,流动相为0.1%甲酸水溶液和0.1%甲酸乙腈溶液,大气压电离源正离子MRM模式检测.蜂蜜和蜂王浆样品的定量下限(LOQ,S/N＞10)为0.5 μg/kg,冻干粉样品的LOQ为1.0 μg/kg.在0.5 ～50.0 μg/L范围内,峰面积与质量浓度呈良好线性,r为0.993 2 ～0.999 5.     

通过式净化-高效液相色谱-串联质谱法测定动物源性食品中42种兽药残留

建立了猪牛肉、虾、鱼等动物源性食品中磺胺类、磺胺增效剂及喹诺酮类共42种兽药残留的通过式净化-高效液相色谱-串联质谱分析方法。样品经0.1%甲酸-乙腈溶液匀浆提取,过PRiME HLB小柱净化,浓缩后流动相溶解。以Waters Atlantis T3色谱柱(150 mm×4.6 mm,3μm)分离,用乙腈和0.1%甲酸为流动相进行梯度洗脱,电喷雾电离正离子源(ESI~+)、多反应监测模式保留时间窗口检测,基质匹配标准工作曲线定量。结果表明,42种兽药在1～100μg/kg范围内呈良好线性关系,相关系数(r)均大于0.998,42种兽药的检出限(S/N3)为1.0μg/kg、定量限为(S/N10)为2.0μg/kg,三个添加水平的回收率在81.1%～115.9%之间,批内、批间的相对标准偏差(RSD)为6.8%～22.1%。本方法具有简便、快捷、灵敏度高、定性准确等特点。     

超高效液相色谱-串联质谱法测定鸡内金中9种磺胺类药物残留

采用超高效液相色谱－串联三重四极杆质谱（UPLC－MS/MS）技术,建立了动物源性中药鸡内金中磺胺甲??唑等9种磺胺类药物残留的检测方法。样品经QuEChERS法提取,离心后上清液经PRiME HLB固相萃取柱净化,采用ACQUITY BEH C18柱（2.1 mm × 100 mm,1.7 μm）分离,以含0.1%甲酸－2 mmol/L乙酸铵的水溶液和含0.1%甲酸的乙腈溶液为流动相进行梯度洗脱,在电喷雾正离子模式下,以动态多反应监测模式（d－MRM）进行检测,外标法定量。结果表明9种磺胺类药物在0～50 ng/mL范围内呈良好的线性关系,相关系数（r2）均不小于0.996 0,方法检出限（LOD,S/N = 3）和定量下限（LOQ,S/N = 10）分别为0.065 4～0.715 7 μg/kg和0.212 2～2.478 μg/kg;在3个加标水平下的回收率为63.2%～88.7%,相对标准偏差（RSD）为0.90%～7.1%。该方法简单、快速、准确,应用该方法筛查10批鸡内金样品,有1批检出磺胺甲??唑残留。     

在线固相萃取/液相色谱-串联质谱法检测饲料中5种喹啉药物残留量

建立了在线固相萃取/液相色谱-串联质谱法检测饲料中5种喹(噁)啉药物的方法.准确称取2 g饲料,用10 mL 0.1％盐酸-甲醇(1:1)提取,提取液用0.2％甲酸稀释10倍,通过双三元液相色谱采用反相在线固相萃取柱在线富集净化,以0.2％甲酸与乙腈梯度洗脱,同时转移至C18色谱柱上进行分离,串联四极杆质谱检测.实验结果表明,5种喹(噁)啉药物在50～ 25 000 μg/kg含量范围内线性良好(r＞0.999);方法的检出限为25 μg/kg,定量下限为50 μg/kg;方法回收率为72.6％～84.6％,批内和批间相对标准偏差(RSD)均小于10％.本方法较传统固相萃取柱净化法更简捷、经济和稳定.     

超高效液相色谱-串联质谱法检测动物源性食品中残留的9种β-受体激动剂

建立了动物源性食品中特布他林、西马特罗、沙丁胺醇、非诺特罗、氯丙那林、莱克多巴胺、克仑特罗、妥布特罗和喷布特罗等9种β-受体激动剂残留检测的超高效液相色谱-串联质谱方法。样品经酶解后,用高氯酸去除蛋白质等杂质,调节上清液的pH值后,分别用乙酸乙酯和叔丁基甲醚进行萃取,再用MCX固相萃取柱净化,然后用Waters Acquity UPLC BEH C18色谱柱(50 mm×2.1 mm,1.7 μm)分离,以0.1%甲酸乙腈溶液和0.1%甲酸水溶液为流动相进行梯度洗脱,外标法定量。结果表明:9种β-受体激动剂在0.25～5 μg/kg的空白添加浓度范围内呈良好的线性关系,相关系数(r)均大于0.990;特布他林等8种药物的检出限为0.1 μg/kg,定量限为0.25 μg/kg;喷布特罗的检出限为0.25 μg/kg,定量限为0.5 μg/kg。从0.5,1和2 μg/kg共3个添加浓度的检测结果可以看出,9种药物的平均回收率为87.1%～108.6%,批内、批间相对标准偏差(RSD)均小于20%。该方法具有简便快捷、灵敏度高、定性准确等特点。     

QuEChERS-超高效液相色谱-串联质谱法测定食用菌中7种荧光增白剂

建立了QuEChERS-超高效液相色谱-串联质谱法(UPLC-MS/MS)测定食用菌中7种荧光增白剂残留量的检测方法.样品前处理采用QuEChERS方法, 食用菌样品用水浸润后, 以甲酸和乙腈提取目标物, C18填料、正丙基乙二胺(PSA)和MgSO4净化, C18色谱柱分离, 乙腈和0.1%甲酸梯度洗脱, 多反应监测(MRM)正离子模式扫描.在优化条件下, 7种荧光增白剂在一定质量浓度范围内线性关系良好, 相关系数均大于0.991, 方法检出限(S/N=3)在0.05~0.40 μg/kg之间, 定量低限(S/N≥10)在0.2~1.3 μg/kg之间, 方法的平均回收率在70.1%~109.2%之间.本方法具有操作简单快捷、灵敏度高等优点.     

亲水作用色谱-串联质谱法测定化妆品中三聚氰胺残留量

建立了化妆品中三聚氰胺的亲水作用色谱-质谱联用（HILIC-MS/MS）检测方法。样品经三氯乙酸溶液提取（脂溶性样品再经正己烷萃取)后,用混合型阳离子交换(MCX)反相固相萃取柱富集净化,用5 mmol/L乙酸铵水溶液(含0.1%甲酸)和乙腈作为流动相,以梯度洗脱方式在ZIC-HILIC色谱柱上实现分离,以电喷雾离子源正离子(ESI+)模式进行质谱分析。三聚氰胺在0.02～0.5 mg/L范围内呈良好线性关系,相关系数为0.9985;方法的检出限(LOD,信噪比(S/N)≥3)为5.0 μg/kg,定量限(LOQ,S/N＞10)为20.0 μg/kg;在0.01～0.1 mg/kg添加浓度范围内,三聚氰胺的平均回收率为84.7%～93.4%,相对标准偏差为4.5%～8.4%。该方法能满足化妆品中三聚氰胺残留量的检测。     

液相色谱-串联质谱法快速筛查马饲料中39种违禁药物

建立了同时快速筛查和确证马饲料中39种赛马违禁药物(包含抗心率失常类药物、抗惊厥类药物、止痉挛类药物、抗疟疾类药物、刺激剂、麻醉剂及大麻酚类药物)的液相色谱串联质谱(HPLC-MS/MS)分析方法。样品粉碎后分别经1 mmol/L HClO4溶液和酸化乙腈溶液提取,并通过混合型固相萃取柱净化。采用Agilent Zorbax SB(10.0 cm×2.1 mm i.d.,3.5 μm) 色谱柱,以0.4%甲酸水溶液和0.4%甲酸乙腈为流动相进行梯度洗脱,正离子多反应监测(MRM) 模式下检测。方法对空白饲料3个加标水平下的平均回收率为58%~116%,相对标准偏差为1.6%~20.4%,各类药物线性良好(r2＞0.99)。方法检出限(S/N≥3)和定量下限(S/N≥10)分别为0.2~25.0 μg/kg和1.0~40.0 μg/kg,其中超过67%药物的检出限在2.5 μg/kg以下。实验结果表明,该方法分析时间短,灵敏度、精密度良好,适用于马饲料中上述几类药物的快速筛查和测定。     

Properties of Star-Branched Polymer Chains Near a Surface

We considered two model systems of star-branched polymers near an impenetrable surface. The model chains were constructed on a simple cubic lattice. Each star polymer consisted of f = 3 arms of equal length and the total number of segments was up to 799. The excluded volume effect was included into these models only and therefore the system was studied at good solvent conditions. In the first model system polymer chain was terminally attached with one arm to the surface. The grafted arm could slide along the surface. In the second system the star-branched chain was adsorbed on the surface and the strength of adsorption was were varied. The simulations were performed using the dynamic Monte Carlo method with local changes of chain conformations. The internal and local structures of a polymer layer were determined. The lateral diffusion and internal mobility of star-branched chains were studied as a function of strength of adsorption and the chain length. The lateral diffusion and internal mobility of star-branched chains were studied as a function of strength of adsorption and the chain length. It was shown that the behavior of grafted and weakly adsorbed chains was similar to that of a free three-dimensional polymer, while the strongly adsorbed chains behave as a two-dimensional system.     

用自动凯氏定氮仪测定水中氨氮

用MgO控制预蒸馏水中的pH值,以硼酸溶液为吸收液,用稀硫酸进行中和滴定,用自动凯氏定氮仪测试水中的氨氮,检测下限为1mg/L,相对标准偏差在0.32%~1.04%范围内,加标回收率为96%~104%,并将该法与纳氏试剂比色法和离子色谱法进行了比较。     

Two Atmospheric-pressure Plasma Sources for Polymer Surface Modification

Two atmospheric-pressure plasma sources were studied. One was a helium plasma generated by a RF discharge, and the other was an air plasma generated by a dielectric barrier discharge (DBD). The two plasma sources were characterized on electron density, emission spectrum, and ozone density. The modification of polyethyleneterephthalate (PET) surfaces by the two plasmas was investigated. PET strips were exposed to the plasma at the exit of the plasma source. Water contact angles were measured for surfaces modified with different processing parameters. The change in contact angles was monitored as a function of time. Modification mechanisms were also investigated.     

Effect of drying temperature and blanching on the degradation of chlorophyll a and b in mint (Mentha spicata Huds.) and basil (Ocimum basilicum): Analysis by high performance liquid chromatography with photodiode array detection

Summary The effect of drying conditions on the preservation of chlorophyll pigments in mint and basil have been investigated in order to determine the effects of drying temperature and whether or not there was a prior blanching.Pigments extracted from fresh and dried samples were analyzed by reversed phase high performance liquid chromatography coupled to a photodiode array detector; isocratic separation was performed on a Zorbax ODS C18 column.The purity of the chromatographic peaks of chlorophylls and breakdown products was investigated. The visible spectra of standard samples of chlorophylls and pheophytins were compared, using least squares normalization with those of peaks from the extracts of fresh and dried mint and basil. The study has shown that chlorophylls were better preserved when drying was preceded by a short blanching; if samples were not blanched before drying, the degradation of chlorophylls a and b was best prevented by drying at low temperatures.     

镍钛合金纤维/有机硅-聚氨酯固相微萃取头的制备及其在水中7种取代苯化合物检测中的应用

以2,4-甲苯二异氰酸酯、聚酯多元醇、羟基硅油为原料,辛酸亚锡为催化剂,环己酮为溶剂,合成有机硅-聚酯型聚氨酯。将此聚合物涂于经氢氧化钾水热处理的镍钛合金纤维丝表面作为固相微萃取涂层,制得固相微萃取头。利用红外光谱法分析了聚合物结构;热重分析法确定了涂层最高使用温度;扫描电子显微镜观察了萃取头的表面形貌。以顶空萃取-固相微萃取-气相色谱法（HS-SPME-GC）测定了水中甲苯、二甲苯、间二氯苯、邻二氯苯、苯甲酸乙酯、硝基苯、苯甲醇7种取代苯化合物的含量。各被测物的色谱峰面积与其质量浓度呈良好的线性关系,相关系数（R²）为0.9926~0.9998,方法的检出限为0.08~0.24 μg/L。实际样品测定的加标回收率为95.9%~105.4%,相对标准偏差为1.4%~5.0%。通过对实际样品的分析,说明制备的固相微萃取头涂层不易脱落、性质稳定,对于水中取代苯类化合物具有很强的吸附能力。     

Automated derivatization for on-line solid-phase extraction-gas chromatography; phenolic compounds

An automated system for derivaatization was coupled on-line with solid-phase extraction-gas-chromatography (SPE-GC). The system was optimized for the determination of phenol and chlorinated phenols in aqueous samples. The test analytes were acetylated with acetic anhydride; proper buffering of the sample was a critical factor. Next, the phenol acetates were enriched on a SPE cartridge and transferred to a GC; two appraoaches were studied. In the first approach, the derivatives were enriched on disposable C18 cartridges (ASPEC type) and desorbed with methylacetate. Aan aliquot of the final eluate was injected on-line the GC by means of a loop-type interface. In the second approach, trace enrichment was performed on 10 × 2 mm i.d. LC-type precolumn packed with polystyrenedivinylbenzene copolymer (PLRP-S) this precolumn was dried with a mitrogen purge and the phenol acetates were desorbed with ethyl acetate which was injectedon-line into the retention gap of the GC under partially concurrent solvent evaporation (PCSE) conditions. The Derivatization-SPE-GC system which was based on the loop-type interface has the advantage of simplicity and easy operation, the main drawback is the impossibility to determine phenol acetates which elute prior to trichlorophenol acetates. With the derivatization-SPE-GC approach using PCSE-based desorption, even the most volatile analyte of the test series, phenol acetate, can be determined successfully. The entire procedure, including the derivatization step, was fully automated and integrated in one set-up. The precision data for the integrated on-line derivatization-SP-FID system were fully satisfactory, with RSD values of 1–12 % at the 1 μg/1 level. When a sample volume of 2.2 ml was analyzed, The detection limits for the chlorinated phenol acetates were in the 0.1–0.3 μg/1 range.     

Synthesis of telechelic methacrylic siloxanes with cycloaliphatic substituents groups for UV-curable applications

Methacrylic functionalized siloxanes were prepared in a two-step process. In the first step, a series of telechelic glycidyl epoxy siloxanes were prepared, substituted with either methyl, cyclopentyl, or cyclohexyl groups. In the second step, the telechelic glycidyl epoxy groups were reacted with methacrylic acid. The reaction was monitored via acid value, and when the acid value was ?10, the reaction was terminated. Characterization of the methacrylic telechelic siloxane polymers were performed using ¹H NMR, ¹³C NMR and FT-IR. The methacrylated siloxanes were formulated with a free radical photo-initiator, UV-cured, and the rate of polymerization was monitored via photo-differential calorimetry. After curing, viscoelastic properties, and oxygen-permeability were evaluated. In addition, X-ray was used to evaluate the structure of the cured films. The rate of polymerization was dependent on substituent and increased with increasing substituent size. The oxygen permeability was dependent on crosslink density, and increased with increasing substituent size. The increase in permeability, and thus free volume was supported by X-ray studies which showed an increase in d-spacing with increasing alkyl size.     

固相萃取-气相色谱/质谱联用测定环境水中噻唑硫磷农药残留

建立了对环境水中噻唑硫磷农药残留进行检测的离线固相萃取-气相色谱/质谱联用(SPE-GC/MS)的方法。固相萃取采用C18柱,用甲醇洗脱;GC/MS采用选择离子监测模式。该方法具有较高的灵敏度和选择性,对环境水中噻唑硫磷的最低检测质量浓度为56.4 ng/L(S/N=3);在0.282~141 μg/L时,响应值与样品浓度呈良好的线性关系;加样回收率大于85.5%,相对标准偏差（RSD）小于4.42%。方法操作简便、快速,可用于施用噻唑硫磷后环境水中痕量农药的监测。     

Optimisation of the chlorthalidone chiral separation by capillary electrochromatography using an achiral stationary phase and cyclodextrin in the mobile phase

The separation of chlorthalidone enantiomers in capillary electrochromatography on an achiral stationary phase when adding a chiral selector, hydroxypropyl-β-cyclodextrin, to the mobile phase, was optimised. The goal was to investigate the feasibility of modelling retention times and resolution when during the optimisation procedure regular replacement of columns is required due to their fragility. Therefore, it is essential that the packing procedure delivers reproducible columns. The optimisation of an existing chlorthalidone separation was chosen as case study. The influence of two factors, chiral selector concentration and organic modifier content, on the responses was modelled. The experiments performed prior to modelling were defined by a central composite design. Results on different columns, obtained under identical experimental conditions, were found comparable and thus modelling was possible in situations where several columns were required to complete a design. A second-order polynomial model was built for both responses. Optimal separations were also predicted using Derringer’s desirability functions. The optimum was found at 33 mM cyclodextrin and 16% (v/v) acetonitrile on two types of columns (with different packing times) leading to a strong reduction in analysis time for an equally good separation compared to the initial conditions. Measured and predicted responses were found comparable, indicating that acceptable models were obtained.     

高效液相色谱法测定辣椒中的辣椒碱和二氢辣椒碱

建立了高效液相色谱法(HPLC)测定辣椒中辣椒碱、二氢辣椒碱的检测方法.实验考察了仪器条件、不同流动相体系、流动相配比、柱温、流速等因素对分离的影响.确定了最佳色谱条件为ZORBAX SB-C18色谱柱(250mm×4.6 mm,5μm);二极管阵列检测器,辣椒碱、二氢辣椒碱的最佳检测波长为280 nm;色谱柱温度为2...