气相色谱法测定土壤中的6种酞酸酯

本文建立了气相色谱法（GC-FID）检测土壤样品中6种酞酸酯类化合物的方法,土壤样品通过二氯甲烷和丙酮（1∶1,v/v）超声提取,经弗罗里硅土固相萃取小柱净化后,用GC-FID检测,用保留时间定性,外标法定量。实验表明该方法对6种酞酸酯类化合物分离效果良好,通过硅胶柱、氧化铝柱、石墨炭黑氨基柱和弗罗里硅土柱回收率实验的比较,结果表明弗罗里硅土柱平均回收率为98.0%～102.5%,方法线性范围0.1～100mg/L,相对标准偏差（n=6）在4.6%～7.2%之间,该方法操作简便、准确,具有较好的实用性。     

丙硫克百威及其代谢物在大米中残留检测

本文研究建立了大米中丙硫克百威及其代谢物的超高效液质质联用测定方法。大米样品经乙腈提取,中性氧化铝同相萃取小柱净化后,通过C18色谱柱分离,正离子扫描,以及多反应监测（MRM）方式对样品中丙硫克百威和克百威的残留量进行定性和定量的分析。该方法测定结果标准偏差为3．86％～6．58％,丙硫克百威及克百威最低检出限为5．0gg／kg,其结果稳定准确,符合残留检测要求。     

超高效液相色谱法测定天然β-胡萝卜素软胶囊中β-胡萝卜素

建立了超高效液相色谱测定天然β-胡萝卜素软胶囊中β-胡萝卜素的方法。样品用石油醚溶解提取,通过中性氧化铝柱,用丙酮＋石油醚（5＋95）洗脱、净化,用ACQUITYUPLCBEHC18（2．1×50mm,1．7um）色谱柱分离,以甲醇为流动相,流速为0．3mL／min,柱温为55℃,用二极管阵列检测器在450nm检测β-胡萝卜素,用外标法定量。结果表明,β-胡萝卜素在0．0—10．0μg／mL范围内有良好的线性关系,相关系数为0．9995,回收率在90％-95％之间。本方法简便快速,结果准确可靠。     

气相色谱法测定水中溴氰菊脂

方法阐明了一种更有效的用C18固相萃取小柱萃取水中溴氰菊脂及测定方法。水样经C18柱萃取石油醚淋洗后，用气相色谱-电子捕获检测法直接测定，加标回收率在89％～93％。RSD为6．2％-12．7％，最低检出限可达0．01ug/L。     

萃取色层分离ICP／MS测定U3O8中痕量杂质元素

本文叙述了结合CL－TBP萃取色层分离,运用ICP／MS测定U3O8中痕量杂质元素B、Ti、Cd、V、Cr、Zn、Mo、Sb、W、Bi的方法。U3O8经硝酸溶解后,采用CL－TBP草林树脂作固定相,5．5mol／L,硝酸作流动相的萃取色层法使杂质元素与铀基体分离,杂质元素淋洗液用ICP／MS测定。取样量为O．5g时,各杂质元素的测定下限为1×10（-8）g／g。方法的重加回收率在88％－116％之间,相对标准偏差小于14％。     

气相色谱-质谱法测定玉米中50种残留农药

粉碎好的玉米使用乙腈超声提取，再经碳十八和活性碳氨基串联固相萃取柱净化，采用GC—EI—MS的选择离子监测（SIM）方式和外标法定量方法，同时分析测定了玉米中的50种农药残留量。该方法回收率在62．8％-119．2％之间，相对标准偏差小于12．1％，50种农药的检出限（LOD）最小为0．8μg／kg，最高为7．2μg／kg。该方法快速、灵敏、准确。各项技术指标满足国内外农药残留检测的要求，能够应用于玉米试样中痕量农药残留的分析。     

RP—HPLC法测定鼠肝组织儿茶酚氧位甲基转移酶活性的研究

建立了反相液相色谱法测定鼠肝组织儿茶酚氧位甲基转移酶（COMT）活性的方法。以3,4-二羟基苯甲酸为底物,测定产物4-羟基-3-甲氧基苯甲酸的生成量计算酶活。色谱柱AgilentZORBAXEclipseXDB—C18（150×4．6mm,5iμmd）,流动相为甲醇／0．7％乙酸水溶液（23／77,v／v）,流速1．0mL／min,检测波长254nm,柱温25％。4-羟基-3-甲氧基苯甲酸的线性范围0．5～20μg／mL,回收率94—98％,RSD小于5％,检测限0．1μg/mL（S／N=3）。结果表明,该方法简便、快速、重复性好,可应用于鼠肝组织中COMT活性的测定。     

液相色谱串联质谱法测定巴鱼中硝基呋喃代谢物的残留量

建立巴鱼中呋喃唑酮、呋喃它酮、呋喃西林和呋喃妥因的代谢物残留量液相色谱-串联质谱的方法。分析物采用电喷雾电离正离子（ ESI ＋）、多反应监测（M RM ）模式检测,内标法定量。本实验对固相萃取法提取和乙酸乙酯提取净化前处理方法进行比对,4种硝基呋喃代谢物的混合标准溶液的浓度在0.5～50ng/mL范围线性良好,相关系数均大于0.9981,4种化合物的检测限为0.5μg/kg。添加浓度1μg/kg、2.5μg/kg、5μg/kg范围内得出4种代谢物固相萃取净化法的回收率在81.1％～104.1％之间,相对标准偏差（RSD）小于5.7％.乙酸乙酯提取净化法的回收率在88.5％～108.2％之间,相对标准偏差（RSD ）小于6.1％。结论证明乙酸乙酯提取法方法前处理简单、快速、稳定性好,适用于大量样品的同时检测。     

微波萃取-气相色谱-质谱法测定皮革制品中富马酸二甲酯

建立了微波萃取气相色谱-质谱测定皮革制品中富马酸二甲酯的方法.以乙酸乙酯为萃取溶剂,采用微波萃取法提取皮革制品中的富马酸二甲酯,萃取液采用中性氧化铝小柱脱脂净化、无水硫酸钠脱水后,进行气相色谱-质谱检测.结果表明,方法检出限为0.1mg/kg,加标回收率为84.2％～ 106.4％,重复测量结果之间的相对标准偏差为2.2％.该方法具有快速、简便、准确、灵敏度高等优点,适用于皮革制品中富马酸二甲酯含量的检测.     

固相萃取-离子色谱法测定乳清粉中的硝酸盐

研究了采用固相萃取-离子色谱法测定乳清粉中的硝酸盐。用30mM的KOH溶液等度淋洗，流速为1．0mL／min，采用AS11-HC型阴离子色谱柱进行分析。在此检测条件下，硝酸盐有很好的线性（r=0．9999）。该方法的最小检出限为500μg／kg，回收率为87．5％-105％，RSD〈5％。实验结果表明，采用固相萃取-离子色谱法测定乳清粉中的硝酸盐，不仅样品前处理简便、快速，且检测结果准确。     

固相萃取净化-气相色谱-三重四极杆串联质谱法同时测定奶粉中多氯联苯和邻苯二甲酸酯

建立了固相萃取净化结合气相色谱-三重四极杆串联质谱法同时检测奶粉中15种多氯联苯(PCBs)和16种邻苯二甲酸酯类化合物(PAEs)。通过对提取条件、净化方法、仪器条件等进行优化,样品经乙腈超声提取,固相萃取小柱净化后,由程序升温气化进样口不分流进样,选择反应监测模式检测。结果表明:PCBs和PAEs分别在5~1000μg/L和3~1000μg/L范围内呈良好的线性关系,相关系数(r^2)均不小于0.9922;方法检出限分别为0.5~3.0μg/kg和0.3~1.0μg/kg,定量限分别为1.5~8.0μg/kg和1.0~3.0μg/kg;实际样品的平均加标回收率分别为72.4%~94.8%和82.4%~107.1%,相对标准偏差均不大于9.1%(n=6)。该方法前处理简单、净化效果好、灵敏度和准确度高,可以实现对样品的同时净化和提取,能够满足实验室样品中多氯联苯和邻苯二甲酸酯的日常检测要求。     

Combined molecular docking,homology modeling and DFT method for the modification of bovine serum albumin (BSA) to improve fluorescence spectroscopy for phthalate acid esters chelated with BSA

While phthalate acid esters (PAEs) cannot fluoresce alone, they can be detected by fluorescence spectroscopy after chelation with bovine serum albumin (BSA). In this study, the types of amino acid residues at the active site of PAEs chelated with BSA were determined using molecular docking technology. A modification scheme of BSA with higher detection sensitivity fluorescence spectroscopy for PAEs was proposed based on the docking results and constructed for a novel BSA structure with a higher detection sensitivity of fluorescence spectroscopy using a homologous modeling method. Density functional theory (DFT) was employed to explore the influence before and after BSA modification on PAEs’ detection through fluorescence spectroscopy. The results showed that the docking scores between BSAs and dimethyl phthalate (DMP), dibutyl phthalate (DBP) and di-n-octyl phthalate (DNOP) were increased up to 26.45%, 16.82% and 16.30%, respectively, indicating that the active site modification of BSA could enhance the binding affinity between BSA and PAEs. The fluorescence intensity of PAEs chelated with modified BSAs were calculated. The fluorescence intensity of fluorescence spectroscopy for DMP, DBP and DNOP chelated with BSAs after modification was increased up to 2.8-, 104.51- and 62.43-fold, respectively, which achieved the purpose of theoretically modifying BSA to improve the detection sensitivity of fluorescence spectroscopy for PAEs.     

Unlubricated sliding and rolling wear of thermoplastic dynamic vulcanizates (Santoprene) against steel

The friction, sliding and rolling wear characteristics of thermoplastic dynamic vulcanizates (TPV; Santoprene^® grades), composed of polypropylene (PP), ethylene/propylene/diene rubber (EPDM) and extender oil, were studied against steel counterparts in dry condition. The composition and basic mechanical properties of the TPV of various hardness (Shore A = 60°, 70° and 80°) were evaluated. The wear performance of the TPVs was investigated in different tribotests, viz. pin-on-plate (POP), cylinder-on-plate (fretting) and rolling ball-on-plate (RBOP), whereby “plate” was always the rubber. From the above tests the coefficient of friction (COF) and specific wear rate were determined. It was established that with increasing hardness usually both COF and the specific wear rate were reduced. Values of the COF and wear rate depended strongly on the configuration and testing parameters of the related tribotests. The wear mechanisms were concluded by inspecting the worn surfaces by white light profilometry and scanning electron microscopy (SEM), respectively, and discussed.     

Adhesion and friction studies of silicon surfaces processed using a microparticle-based method

A surface processing method that combines electrostatic deposition of microparticles and dry etching is utilized to modify the surface topography of silicon surfaces to reduce adhesion and friction force. Microscale adhesion and friction tests were conducted on flat (smooth) and processed silicon surfaces with a low elastic modulus thermoplastic rubber (Santoprene) probe that allowed a large enough contact area to observe the feature size effect. Both adhesion and friction force of the processed surfaces were reduced comparing to that of the flat surfaces.     

Nanocomposite polymer layers for molecular tribology

We discuss a novel strategy for the formation of elastomeric boundary lubrication coatings from block copolymers grafted to a reactive interface of a silicon substrate. We demonstrate molecularly thick thermoplastic elastomeric films with promising microtribological properties. These films are composed of an elastomeric rubber phase reinforced by the net of glassy nanodomains. These elastomeric layers are extremely wear resistant under shear stresses due to the unique combination of a chemically grafted elastic matrix capable of tremendous reversible deformation (500–1000%) stabilized by a chemically interconnected nanodomain net.     

Oily Nanocoatings

Tribological performance of molecular thermoplastic elastomeric films grafted onto a silicon surface was enhanced by adding a minute amount of paraffinic oil, which was adsorbed by the rubber matrix. The nanocomposite films show bimodal distribution of the surface elastic modulus, caused by the nanodomain structure. Minute amounts of oil, trapped within the rubber phase after evaporation, modified the nanotribological properties of these layers. We observed a significant decrease of the friction coefficient by 40%, along with a lower elastic modulus of the rubber phase. We suggest that under high shear stresses and sliding velocity, oil molecules can be compressed out of the bulk to the surface, facilitating instant local lubrication of the contact area.     

Nanotribological behavior of tethered reinforced polymer nanolayer coatings

We fabricated molecularly thick thermoplastic elastomeric films with organized microdomain structure and intriguing nanotribological properties. Molecular films from poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) were obtained by a melt/solution grafting to a functionalized silicon surface modified with epoxy-terminated self-assembling monolayers. We varied the thickness of grafted block–polymer films from 1.35 nm (disordered polymer layer) to 9 nm (well defined nanophase structure) and tested their friction, adhesion, shear and wearing properties on a microscale with scanning probe microscopy. Tethered SEBS monolayers, composed of a rubber matrix reinforced by a two-dimensional net of glassy polystyrene (PS) microdomains, possess a friction coefficient as low as 0.02 and shear strength in the range 0.15–1.5 GPa. Chemically tethered SEBS monomolecular films are much more stable under shear stresses than conventional molecular coatings.     

Towards self-lubricated nanocoatings

The microtribological performance of molecularly thick (<10 nm) thermoplastic elastomeric films grafted to a silicon surface was enhanced by adding a minute amount of paraffinic oil, which was adsorbed from vapor phase and held by the rubber matrix. We studied the kinetics of polymer swelling in oil and the formation of polymer gels. We observed that a vast majority of adsorbed oil evaporated from the ultrathin polymer coating leaving a minute amount of oil trapped within the rubber phase. This resulted in a dramatic enhancement of the microtribological performance of the grafted polymer gel layers. These polymer gel layers exhibited a very steady friction response and a small value of the coefficient of friction as well as greater wear-resistance as compared to the initial polymer coating. The performance of polymer gel coatings was much better than the performance of a classic ‘boundary lubricant’ for silicon surfaces, an alkylsilane self-assembled monolayer. The approach proposed demonstrated a new efficient route towards enhanced tribological performance of ultrathin polymer coatings.     

Influence of solid lubricants and fibre reinforcement on wear behaviour of polyethersulphone

Polyethersulphone (PES), is an amorphous, brittle and high temperature engineering thermoplastic. Two composites of PES containing short glass fibres (GF) and solid lubricants viz. PTFE and MoS₂; and two composites containing short carbon fibre (CF) [30% and 40%] were selected for the present studies. Compositional analysis of selected materials was done with various techniques such as gravimetry, solvent extraction and thermal analysis viz. thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). These materials were studied for adhesive and abrasive wear performance by sliding against a mild steel disc and silicon carbide abrasive paper respectively, under different loads. It was observed that GF reinforcement along with incorporation of solid lubricants (PTFE and MoS₂) enhanced the wear performance of PES by an order of two. In the case of solid lubricants, PTFE proved to be more beneficial than MoS₂. CF reinforcement, however, proved to be the most effective in enhancing wear performance of PES. PES reinforced with 40% CF exhibited a specific wear rate in the order of 10⁻¹⁶m³/Nm which is considered to be very good for the thermoplastic composite. In the case of abrasive wear behaviour, however, incorporation of fibres or solid lubricants deteriorated the performance of the neat matrix. SEM was employed to investigate the wear mechanisms.     

气相-离子阱串联质谱技术对塑料中痕量邻苯二甲酸酯的检测

探索建立对塑料中痕量邻苯二甲酸酯的GC／MS检测方法。[方法]塑料样品经研磨仪粉碎及微波萃取后。利用离子阱GC／MS的SCAN模式和SIM模式分别对萃取液中邻苯二甲酸二丁酯-（DBP）、邻苯二甲酸丁苄酯（BBP）、邻苯二甲酸二（2-乙基己基）酯（DEHP）、邻苯二甲酸二正辛酯（DNOP）、邻苯二甲酸二异壬酯（DINP）和邻苯二甲酸二异癸酯（DIDP）等六种邻苯二甲酸酯含量进行定性和定量分析。[结果]该方法对塑料中BBP、DBP、DEHP、DNOP的检出限（s／N=3）皆小于0．015mg／kg,对DIDP、DINP的检出限（s／N=3）为小于2．5mg／kg,六种PAEs加标回收率为83％～95％,RSD（n=4）为2％-7％。I结论]该方法满足对塑料中以上六种邻苯二甲酸酯的痕量检测。