高效液相色谱-蒸发光散射法测定食品中的单糖、双糖、低聚果糖和糖醇

建立了食品中常用的木糖、果糖、葡萄糖、蔗糖、麦芽糖、乳糖、蔗果三糖、蔗果四糖、蔗果五糖、赤藓糖醇、木糖醇、甘露糖醇、麦芽糖醇等13种单糖、双糖、低聚果糖和糖醇的高效液相色谱同时分离检测的方法。该法采用NH₂色谱柱,以乙腈-水为流动相梯度洗脱,蒸发光散射检测器检测;13种糖在0.1~5 g/L内均具有良好的线性关系,检出限均在0.1 g/L以下,精密度(RSD)为2.69%~7.21%,回收率为96.1%~105.2%,结果较为理想。将该法用于实际样品检测,结果显示食品标签明示和实际成分相差较大。     

高效阴离子交换色谱-脉冲安培检测法测定乳粉中的低聚果糖

建立了测定乳粉中低聚果糖的高效阴离子交换色谱-脉冲安培检测(HPAEC-PAD)方法。样品经50%(v/v)乙醇水溶液提取,On Guard RP柱除脂,CarboPac PA200阴离子交换色谱柱(250 mm×3 mm)分离。采用水、0.2 mol/L NaOH溶液和0.4 mol/L NaAc溶液三元梯度淋洗,流速为0.4 mL/min,柱温为30 ℃,进样量为25 μL,脉冲安培检测器检测。蔗果三糖、四糖、五糖在0.05~10 mg/L范围内线性关系良好,相关系数(r²)> 0.9993;定量限分别为0.02、0.005和0.02 mg/L。在0.5、1.0、5.0 mg/L添加水平下,蔗果三糖、四糖、五糖的平均回收率为86.0%~114.0%。该方法处理简单、结果准确、灵敏度高,适用于乳粉中低聚果糖的测定。     

高效阴离子交换色谱分离-脉冲安培检测法测定烟草料液中的糖、糖醇和醇类化合物

建立了高效阴离子交换色谱分离-脉冲安培检测法测定烟草料液中的糖、糖醇以及醇类化合物的方法。以NaOH为淋洗液,在CarboPac MA1阴离子交换柱上等度分离了肌醇、甘油、丙二醇、半乳糖醇、木糖醇、山梨醇、甘露醇、葡萄糖、果糖、蔗糖、甘露糖和半乳糖等12种化合物。对影响分离和检测的条件进行了优化,并在此优化条件下分析了烟草料液中的糖、糖醇以及醇类化合物。12种化合物的检出限为2.0~216μg/L(25.0μL进样,以3倍信噪比计算检出限)。12种化合物浓度为1~5mg/L的标准溶液连续7次进样的RSD为0.7%~4.3%。方法对烟草料液中12种化合物的加标回收率为80%~108%。方法灵敏、高效、简便、快捷。     

高效液相色谱法同时检测化妆品中12种直接染料

建立了高效液相色谱分离检测化妆品中12种直接染料的方法。采用XB-C18色谱柱分离,以乙腈-0.02 mol/L乙酸铵水溶液（pH 9.0）为流动相梯度洗脱,二极管阵列检测器检测。结果表明,12种直接染料在线性范围内具有良好的线性关系,相关系数均> 0.999;方法的检出限为0.017~1.7 μ g/g,回收率为85.6%~113.4%,相对标准偏差为1.0%~7.7%;日内和日间精密度分别为0.4%~6.5%和0.2%~7.5%。该法简单快速,灵敏度高,定量准确可靠,适用于化妆品中直接染料的日常检测。     

高效液相色谱/二极管阵列法快速测定白酒、配制酒与葡萄酒中5种人工合成甜味剂

建立了一种快速检测白酒、配制酒和葡萄酒中安赛蜜、糖精钠、阿斯巴甜、阿力甜及纽甜5种人工合成甜味剂的高效液相色谱分析方法。采用C_(18)柱为分离柱,对流动相的组成和洗脱方式、检测波长等参数进行优化。结果表明,以乙腈和0.02 mol/L硫酸铵(p H 4.4)溶液为流动相,梯度洗脱,柱温40℃,可使5种人工合成甜味剂在15 min内实现基线分离。最佳检测波长下,5种甜味剂在4~200 mg/L浓度范围内呈良好的线性关系,相关系数均大于0.999。样品加标回收率为95.2%~103.2%,相对标准偏差(n=5)均不大于3.4%。该方法简便、快捷、准确、灵敏度较高,适用于白酒、配制酒和葡萄酒等各类酒中5种人工合成甜味剂的快速检测。     

固相萃取/超高效液相色谱-串联质谱法快速测定不同水体中5种人造甜味剂、6种造影剂及咖啡因

建立了快速检测不同水样(地表水、污水处理厂进水和出水)中5种人造甜味剂、6种造影剂和咖啡因的超高效液相色谱-串联质谱(UPLC-MS/MS)方法。利用HR-X固相萃取柱对过滤后的水样进行富集净化。采用Zorbax SB-C_(18)色谱柱分离,电喷雾正模式(ESI+)和负模式(ESI-)下分别以乙腈-水(10 mmol/L乙酸铵,0.01%甲酸)和乙腈-水(5 mmol/L乙酸铵,1 mmol/L Tris)为流动相,多反应监测模式(MRM)检测。各目标化合物在5~5 000μg/L范围内线性关系良好,相关系数均大于0.998。地表水、污水处理厂进水和出水的回收率为70%~120%,相对标准偏差(RSD)为0.8%~19.0%,方法检出限(MDL)分别为0.43~13.8、1.80~34.8、2.30~134 ng/L。应用该方法对广州某污水处理厂进水和出水及受纳河流河水进行检测,除阿斯巴甜、碘他拉酸、碘普罗胺、碘美普尔外,其他物质均有检出且浓度较高。该方法准确、灵敏、操作简便,适用于多种环境水样中人造甜味剂、造影剂和咖啡因的分析检测。     

超高效液相色谱串联质谱法测定饲料中10种脂溶性工业染料

建立了以超高效液相色谱串联四极杆质谱(UPLC-MS/MS)检测鸡和鱼类饲料中10种脂溶性染料的方法。样品经过甲醇振荡提取通过固相萃取小柱去除基质干扰。在waters BEH C_(18)柱子上,乙腈和0.2%(V:V)甲酸,10 mmol/L甲酸铵的水为流动相,利用梯度洗脱将各目标化合物分离,采用质谱多反应监测(MRM)模式进行定量检测。染料在两种饲料中检出限(LOD)为1~5μg/kg,定量限(LOQ)为2~10μg/kg,在鱼饲料中,回收率为80.3%~113.2%,相对标准偏差为1.4%~11%,在鸡饲料中回收率为79.6%~115.4%,相对标准偏差为1.6%~15%。     

固相萃取-高效液相色谱-质谱联用法同时测定食品中9种人工合成甜味剂

建立了固相萃取-高效液相色谱-串联质谱快速检测食品中安赛蜜、糖精钠、甜蜜素、三氯蔗糖、阿斯巴甜、阿力甜、纽甜、甘素及新橙皮甙二氢查尔酮等9种人工合成甜味剂的方法。样品中的甜味剂经三乙胺缓冲溶液（pH 4.5）提取，采用亲水亲脂平衡填料固相萃取柱净化，经Phenomenex Knietex^® F5色谱柱（100 mm×2.1 mm，2.6 μm）分离，以0.1%（v/v）甲酸-5 mmol/L甲酸铵溶液和甲醇为流动相，进行梯度洗脱，以电喷雾离子源正负离子切换多反应监测（MRM）模式进行质谱检测。采用内标法定量，进一步降低样品基质效应的影响。结果表明：本方法在去除样品基质干扰方面取得良好效果，9种甜味剂的检出限和定量限分别在2~30 μg/L和6~100 μg/L之间，在各自的线性范围内线性关系良好（相关系数r²>0.999）。9种甜味剂空白样品在3个水平下的加标回收率在86.3%~106.3%之间，相对标准偏差（RSD）在1.2%~5.9%之间。本方法快捷、高效、准确可靠，可用于复杂食品基质中9种人工合成甜味剂的快速检测。     

凝胶色谱/超高效液相色谱-串联质谱法测定饲料中16种脂溶性染料的研究

应用凝胶色谱/超高效液相色谱-串联三重四极杆质谱建立了饲料中16种脂溶性染料测定的新方法。样品经20 m L乙酸乙酯-环己烷(1∶1)提取,凝胶色谱系统净化后,以0.1%甲酸溶液-甲醇为流动相进行梯度洗脱,各脂溶性染料经C18柱得到良好分离。16种染料在2~100μg/L范围内线性关系良好,相关系数(r2)不小于0.99。其检出限为25μg/kg,定量下限为50μg/kg。饲料样品在低、中、高3个加标浓度下,16种脂溶性染料的回收率为66.4%~108.5%,结果表明方法适用于饲料中16种脂溶性染料的检测。该方法操作简单、准确、杂质干扰少。     

漩涡辅助液液微萃取-气相色谱法测定水样中痕量多环芳烃

建立了漩涡辅助分散液液微萃取(VAEDLLME)结合气相色谱测定环境水样中12种多环芳烃的方法。对萃取剂种类和体积、漩涡时间以及盐浓度的影响等参数进行优化。实验结果表明,方法线性范围为0.1~5.0μg/L,相关系数r≥0.9851,检出限为0.001~0.01μg/L,加标回收率为95.0%~124.4%,相对标准偏差(RSD)为1.4%~27%。方法适用于环境水样中12种多环芳烃的分析检测。     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von vier bindungsisomeren Trichlorotrirhodanoosmaten(IV)

Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of four Linkage Isomeric Trichlorotrirhodanoosmates(IV) By treatment of fac-[OsCl₃I₃]^2? with (SCN)₂ in dichloromethane the linkage isomers fac-[OsCl₃(NCS)₃]^2? ( 1 ), mer-[OsCl₃(NCS)₂^c(SCN)]^2? ( 2 ), mer-[OsCl₃(NCS)(SCN)₂^t]^2? ( 3 ), and mer-[OsCl₃(NCS)(SCN)₂^c]^2? ( 4 ) are formed which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. X-Ray structure determinations have been performed on single crystals of fac-(Ph₄As)₂[OsCl₃(NCS)₃] (triclinic, space group P1 , a = 12.142(5), b = 13.233(5), c = 19.300(5) Å, α = 98.642(5)º, β = 100.509(5)º, γ = 112.514(5)º, Z = 2), mer-(Ph₄As)₂[OsCl₃(NCS)₂^c (SCN)] · acetone (triclinic, space group P1 , a = 11.707(5), b = 13.238(5), c = 19.048(5) Å, α = 75.960(5)º, β = 88.981(5)º, γ = 69.999(5)º, Z = 2), mer-(Ph₄As)₂[OsCl₃(NCS)(SCN)₂ ^t] (triclinic, space group P1, a = 10.6861(12), b = 11.6587(5), c = 12.5232(5) Å, α = 112.069(8)º, β = 95.052(8)º, γ = 92.559(7)º, Z = 1) and mer-(Ph₄As)₂[OsCl₃(NCS)(SCN)₂ ^c] · 2acetone (triclinic, space group P1 , a = 11.444(5), b = 14.661(5), c = 15.830(5) Å, α = 75.790(5)º, β = 80.273(5)º, γ = 75.205(5)º, Z = 2). The complex anions are completely ordered. The via N or S coordinated thiocyanate groups are located nearly direct above one of the cis-positioned Cl ligands with Os? N? C angles of 169.1º, 171.5º, 175.7º ( 1 ), 175.6º, 178.6º ( 2 ), 172º ( 3 ), and 173.1º ( 4 ) and Os? S? C angles of 106.2º ( 2 ), 106.1º, 106.6º ( 3 ), 105.1º, and 108.2º ( 4 ). Using the molecular parameters of the X-Ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu₄N) salts of all four linkage isomers have been assigned by normal coordinate analyses based on a modified valence force field. The valence force constants are f_d(OsN) = 1.71 ( 1 ), 1.46 and 1.62 ( 2 ), 1.69 ( 3 ), and 1.61 ( 4 ), f_d(OsS) = 1.27 ( 2 ), 1.36 ( 3 ), 1.32, and 1.49 mdyn/Å ( 4 ). Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von vier bindungsisomeren Tetrachlorodirhodanoosmaten(IV)

Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of Four Linkage Isomeric Tetrachlorodirhodanoosmates(IV) By treatment of cis- or trans-[OsCl₄I₂]^2? with (SCN)₂ in dichloromethane the linkage isomers cis-[OsCl₄(NCS)₂]^2? ( 1 ), trans-[OsCl₄(NCS)(SCN)]^2? ( 2 ), cis-[OsCl₄(NCS)(SCN)]^2? ( 3 ) and trans-[OsCl₄(SCN)₂]^2? ( 4 ) are formed which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-Ray structure determinations on single crystals of cis-(Ph₄As)₂[OsCl₄(NCS)₂] (triclinic, space group P1 , a = 10.019(5), b = 11.702(5), c = 21.922(5) Å, α = 83.602(5)°, β = 85.718(5)°, γ = 73.300(5)°, Z = 2), trans-(Ph₄As)₂[OsCl₄ · (NCS)(SCN)] (monoclinic, space group P2₁/c, a = 18.025(5), b = 11.445(5), c = 23.437(5) Å, β = 94.208(5)°, Z = 4), cis-(Ph₄As)₂[OsCl₄(NCS)(SCN)] (triclinic, space group P1 , a = 10.579(5), b = 11.682(5), c = 22.557(5) Å, α = 81.073(5)°, β = 85.807(5)°, γ = 87.677(5)°, Z = 2) and trans-(Ph₄As)₂ · [OsCl₄(SCN)₂] (triclinic, space group P1 , a = 10.615(5), b = 11.691(5), c = 11.907(5) Å, α = 111.314(5)°, β = 96.718(5)°, γ = 91.446(5)°, Z = 1) reveal the complete ordering of the complex anions. The via N or S coordinated thiocyanate groups are located nearly direct above one of the cis-positioned Cl ligands with Os? N? C angles of 171.2° and 174.3° ( 1 ), 162.3° ( 2 ), 172° ( 3 ) and Os? S? C angles of 108.3° ( 2 ), 105.7° ( 3 ) and 105.5° ( 4 ). Using the molecular parameters of the X-Ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu₄N) salts of all four linkage isomers are assigned by normal coordinate analyses based on a modified valence force field. The valence force constants are f_d(OsN) = 1.59 ( 1 ), 1.67 ( 2 ), 1.60 ( 3 ) and f_d(OsS) = 1.27 ( 2 ), 1.31 ( 3 ) and 1.32 mdyn Å^?1 ( 4 ). Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved.     

Comparative Thermogravimetric Studies of Poly(ether-ketone/sulfone) Imides and Their Parent Polymers: I. Poly(ether-ketone/sulfone) ethylimide

Thermogravimetry (TG) was employed to study the thermal degradation kinetics of poly(etherketone/sulfone)ethylimide (PEK-IE and PES-IE). The corresponding decomposition activation energies and reaction orders were obtained and the comparison was made with their parent polymerspoly(ether-ketone/sulfone) with Cardo group (PEK-C and PES-C). The results show that the degradation activation energies of PEK-IE and PES-IE were lower than that of PEK-C and PES-C; and two stages of the degradation process were found for all the four polymers. For PEK-IE and PES-IE, the activation energies in the first decomposition stage are much lower than that in the second stage and the two stages can be taken as slow induction and fast degradation, whereas for PEK-C and PES-C the activation energies in the first decomposition stage are larger than that in the second stage, and the two stages can both be taken as two fast degradation stages. The decomposition mechanism of the two stages was also speculated.This revised version was published online in November 2005 with corrections to the Cover Date.     

Darstellung und Kristallstruktur von (n-Bu4N)3[Ir(NCS)(SCN)5]

Preparation and Crystal Structure of (n-Bu₄N)₃[Ir(NCS)(SCN)₅] The evaporated ethanolic extrakt of the reaction product of K₃[IrCl₆] and HNO₃, refluxed with an aqueous KSCN solution yields a mixture of the linkage isomers [Ir(NCS)_n(SCN)_6?-n]^3?, n = 0? 2, and small amounts of linkage isomeric chloropentarhodanoiridates(III), from which [Ir(NCS)(SCN)₅]^3? has been isolated by ion exchange chromatography on DEAE-cellulose. The X-Ray structure determination on a single crystal of (n-Bu₄N)₃[Ir(NCS)(SCN)₅] (monoclinic, space group P 2₁/a, a = 17.513(5), b = 32.607(5), c = 23.661(5) Å, β = 94.757(5)°, Z = 8) confirms the existance of a heteroleptic hexakis(thiocyanato(N)-thiocyanato(S))iridate(III) with an Ir? N distance of 2.03 Å and Ir? S bond lengths between 2.29 and 2.38 Å. The SCN groups with angles between 166 and 175° are nearly linear with Ir? S? C angles from 99.9 to 109.4°. The Ir? N? C angles of the two crystallographic independent anions are 166 and 174°.     

SYNTHESIS AND CHARACTERIZATION OF METAL COMPLEXES WITH AMPICILLIN

Abstract

The reaction, in water, of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with sodium ampicillinate at room temperature has allowed isolation of dimers with the following general formula [M(amp)Cl]₂ × nH₂O (n = 1.5?3.2). The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibilities and spectroscopic methods (IR, Raman, EPR and UV-Visible). A dinuclear structure based on octahedrally coordinated metal ions is proposed.     

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性;均苯四甲酸二酐;联苯四羧酸二酐;二羟基联苯胺;聚酰亚胺;聚苯并噁唑;耐热性     

Thermal Degradation of Poly(ε-caprolactone), Poly(L-lactic acid) and their Blends with Poly(3-hydroxy-butyrate) Studied by TGA/FT-IR Spectroscopy

Summary: The thermal degradation behavior of poly(ε-caprolactone) (PCL) and poly(L-lactic acid) (PLA) have been studied in different environment. It was found that these polymers undergo completely different degradation processes in nitrogen and oxygen atmosphere. In oxygen environment PCL and PLA mainly decompose to CO₂, CO, water and short-chain acids. In nitrogen atmosphere PCL releases 5-hexenioc acid, CO₂, CO and ε-caprolactone, whereas PLA decomposes to acetaldehyde, CO₂, CO and lactide. The polymer blends of poly(3-hydroxybutyrate) (PHB) with PCL and PLA decompose similar to the individual homopolymers with crotonic acid as the initial decomposition product of PHB.     

Energy relationship and the polarization of C_(60) cage in the endohedral complexes (X@C_(60))

In this paper, we carry out the calculation on the system (X@C60)(X=Li, Na, K, Kb, Cs; F, Cl, Br, I), where the position of X changes along 5 typical symmetry directions. For the calculation of quantum chemistry we use EHMO/ASED method, for the calculation of molecular mechanics we use Buckingham potential (exp-6-1) function, and for the calculation of thermo-chemical cycle we use individually isolating the processes such as the structure variation, charge transfer and charge distribution, and their interactions etc. The calculation results show that (1) In the region of radius r≈0.2 nm of the Ceo cage, the potential field is nearly spherical; (2) Except for Li and Na, the systems are the most stable with minimum energies at the center of C60 cage. For Li and Na, the systems are the most stable with minimum energies at r≈0.16 nm and r≈0.13 nm, respectively. In view of the interactive region of chemical bonds, the interactions between X and the C60 cage do not belong to the classical chemical bonds; (     

铜在3%NaCl溶液中腐蚀行为的光电化学研究

Cu以其优异的导电性、导热性和易加工性广泛用于工农业生产中．自然Cu的腐蚀和防腐成为人们很关注的问题．人们已经注意到，Cl-对Cu的腐蚀有影响，并进行过一些研究．但目前使用光电化学方法研究这一问题的文章尚不多见，特别是利用测量开路光电压及其瞬态波形这一现场的、无损的、灵敏的监测方法研究户对Cu电极腐蚀全过程的文章尚未见到．本文正是利用如上方法及XPS，AES方法，研究了Cl-对Cu电极腐蚀的全过程，取得了一些有意义的结果．1实验方法Cu电极用99．99％（质量分数）的Cu制成，面积约为39mm2；电极底部由Cu导线焊接引出，…     

On the morphological behavior of ABC miktoarm stars containing poly(cis 1,4-isoprene), poly(styrene), and poly(2-vinylpyridine)

Fundamental understanding of microphase separation in ABC miktoarm copolymers is vital to access a plethora of nonconventional morphologies. Miktoarm stars based on poly(cis 1,4-isoprene) (I), poly(styrene) (S), and poly(2-vinylpyridine) (V) are model systems, which allow systematic studies of the effects of composition, chemical microstructure, and temperature on the thermodynamics of microphase separation. Eleven ISV-x (I:S:V = 1:1:x, v:v:v) miktoarm copolymers were synthesized by anionic polymerization affording well-defined copolymers with a variable V arm. Equilibrium bulk morphologies of all samples, as evidenced by small-angle X-ray scattering, transmission electron microscopy (TEM), and self-consistent field theory, showed a systematic transition from lamellae (x ≈ 0–0.2) to [8.8.4] tiling (x ≈ 0.6–0.9) to cylinders in undulating lamellae (x ≈ 2–4) and, finally, to hexagonally packed core–shell cylinders (x ≈ 5–8). Chemical microstructure of the I arm [poly(cis 1,4-isoprene)] versus poly(3,4-isoprene) is shown to play important role in affecting morphological behavior. To reconcile differences between ISV-x star morphologies reported in the literature and those reported herein, even for the same composition, effects of the microstructure of I arm on the Flory–Huggins parameter between I and V arms were taken into account in a qualitative manner. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1491–1504