15种中药材中砷的形态分析

利用高效液相色谱(HPLC)与电感耦合等离子体质谱(ICP-MS)联用技术对6种砷形态[砷胆碱(AsC)、砷甜菜碱(AsB)、三价砷As(Ⅲ)、二甲基砷酸(DMA)、甲基砷酸(MMA)和五价砷As(Ⅴ)]进行了分离,测定了0 ～100 μg/L范围内6种砷形态的混合标准工作曲线,相关系数(r2)优于0.990,方法检出限均为0.2 μg/L.采用甲醇-水(体积比1 : 1)超声法提取了15种中药材中的砷形态,用HPLC-ICP-MS进行分析,结果表明,15种中药材中存在的主要砷形态是有毒的As(Ⅴ),另外还有少量的砷甜菜碱和砷胆碱,并且动物用药中的有机砷含量明显高于植物用药.     

高效液相色谱-电感耦合等离子体质谱联用测定鸡肉及鸡肝中10种砷形态化合物

建立了一种有效分离检测鸡肉及鸡肝样品中洛克沙砷(ROX)、阿散酸(ASA)、硝苯胂酸(NPAA)、卡巴胂(CBS)、砷酸(AsⅤ)、亚砷酸(AsⅢ)、一甲基胂酸(MMA)、二甲基胂酸(DMA)、砷甜菜碱(As B)和砷胆碱(As C)共10种砷形态化合物的高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)分析方法。采用10%甲醇为提取液,碳酸铵溶液为流动相,以阴离子分析柱将样品提取液进行分离,最后进行ICP-MS测定。10种砷形态化合物在0.1~100μg/L范围内线性关系良好,相关系数(r2)均大于0.999,检出限为0.3~1.5μg/kg,定量下限为1.0~5.0μg/kg,加标回收率为81.3%~97.7%,相对标准偏差为0.1%~3.5%。该法重现性好、灵敏度高,且采用组织研磨仪机械振荡5 min即可成功提取10种砷形态化合物,与常规水浴加热振荡提取相比更加简便、高效。该法适用于鸡肉及鸡肝样品中10种砷形态化合物的同时检测,通过对实际样品的分析测定,在鸡肝样品中检出阿散酸和亚砷酸。     

HPLC-ICP/MS联用同时分析中药材中的多种形态砷

利用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP/MS)对中药材中的6种砷的形态(三价砷(As(Ⅲ))、五价砷(As(Ⅴ))、二甲基砷酸(DMA)、甲基砷酸(MMA)、砷甜菜碱(AsB)和砷胆碱(AsC))进行了同时分析.采用1.2mol/,L HCl浸提,Hamilton PRP-X100阴离子交换色谱柱分离...     

高效液相色谱-电感耦合等离子体质谱法测定禽类生物样品中7种砷形态

采用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)联用技术测定禽类生物样品中砷甜菜碱(AsB)、二甲基砷(DMA)、As(Ⅲ)、一甲基砷(MMA)、As(Ⅴ)、阿散酸(ASA)和硝苯砷酸(NPAA)等7种砷形态。以人工胃液超声振荡法提取禽类生物样品中的砷,采用Dionex IonPacTM AS19阴离子交换柱分离7种砷形态,并用ICP-MS测定其含量。各砷形态的质量浓度在一定范围内与峰面积呈线性关系,检出限(3s,以砷计)在0.070~0.099μg·L~(-1)之间。加标回收率在74.0%~112%之间,测定值的相对标准偏差(n=6)在2.0%~5.9%之间。采用该方法分析矿区禽类生物样品,各砷形态含量的测定值之和与ICP-MS测得的总砷含量基本一致。     

高效液相色谱-电感耦合等离子体质谱联用技术测定水产类膳食中5种砷形态的方法研究

采用高效液相色谱(HPLC)和电感耦合等离子体质谱(ICP-MS)联用技术建立了三价砷As(Ⅲ)、砷甜菜碱(AsB)、二甲基砷酸(DMA)、一甲基砷酸(MMA)、五价砷As(Ⅴ)5种砷形态的分析方法。采用超声溶剂提取法对水产类膳食样品和带鱼等水产品进行前处理后,对砷形态进行分析。实验表明,5种砷化合物的线性范围为2.5~500μg/L,相关系数(r)均大于0.999 0,检出限为0.6~0.9μg/L,RSD均小于5%。采用加标回收考察方法的准确性,加标回收率为87%~124%。样品的测定结果显示,水产品及水产类膳食中砷形态的主要存在形式为砷甜菜碱。     

毛细管电泳法进行化妆品中砷的形态分析

从样品前处理、毛细管电泳修饰、进样方式、分离模式和检测条件等方面对毛细管电泳法研究化妆品中砷的形态进行讨论。在不同pH值的缓冲溶液中,用毛细管电泳法进行化妆品中砷的形态分析,测定波长为197nm。采用磷酸盐缓冲溶液,化妆品中As(Ⅲ)、二甲基胂(DMA)、对氨苯基胂酸(ANA)、一甲基胂(MMA)和As(V)等5种形态的砷可通过毛细管电泳法得到有效分离。     

离子色谱-电感耦合等离子体质谱法测定地下水中4种形态砷的含量

采用离子色谱-电感耦合等离子体质谱法(IC-ICP-MS)测定地下水中4种形态砷[As(Ⅲ)、As(Ⅳ)、一甲基胂酸、二甲基胂酸]的含量。水样在IonPac AS14阴离子色谱柱上分离,采用IonPac AG14阴离子保护柱,以碳酸氢铵为流动相进行梯度洗脱,4种砷形态在15min内完全分离。在进样量25μL时,4种形态砷的线性范围为0.50~200μg·L-1,检出限在0.03~0.06μg·L-1之间,加标回收率在97.0%~102%之间。此方法用于测定地下水样,测定结果与电感耦合等离子体质谱法的结果相吻合。     

高效液相色谱-(紫外)氢化物发生原子荧光光谱法测定南极磷虾及其制品中6种砷形态

建立了南极磷虾及其制品中6种砷形态的高效液相色谱-(紫外)氢化物发生原子荧光光谱(HPLC-(UV) HG-AFS)分析方法,对流动相浓度及pH值、泵速和负高压等条件进行了优化。在最佳实验条件下,亚砷酸(As(Ⅲ))、砷酸(As(Ⅴ))、一甲基砷酸(MMA)、二甲基砷酸(DMA)、砷甜菜碱(AsB)和砷胆碱(AsC)在5～100μg/L范围内线性关系良好(r~20.999 0),检出限(LOD,S/N≥3)均为0.01 mg/kg,定量下限(LOQ,S/N≥10)均为0.03 mg/kg;在0.01、0.05、0.10 mg/kg加标水平下,回收率为89.2%～108%,相对标准偏差(RSD,n=6)为3.4%～14%。采用该方法测定了南极磷虾及其制品中6种砷形态,无机砷(AsⅢ和AsⅤ)含量均低于水产品及其制品中无机砷的国家限量标准。该方法操作简单,适用范围广,结果准确可靠,可用于南极磷虾及其制品中砷的形态分析。     

利用氢化物发生-冷阱捕集-原子吸收光谱联用技术测定雄黄染毒大鼠血中砷的含量

采用氢化物发生-冷阱捕集-原子吸收光谱法(HG-CT-AAS)测定了雄黄染毒大鼠血中不同形态砷的含量.结果表明,雄黄在大鼠体内的代谢产物为无机砷、一甲基胂酸和二甲基胂酸,其中二甲基胂酸是主要代谢产物;3种形态砷的精密度、准确度、回收率及线性关系良好.     

高效液相色谱-氢化物发生-原子荧光光谱法检测紫菜中的砷形态

测定了4种中国紫菜样品的总砷含量并且分析了紫菜中的砷形态。紫菜经电热消解、ICP-AES测定,总砷含量为14.0～42.1 mg/kg。以高效液相色谱-氢化物发生-原子荧光光谱法(HPLC-(UV)-HG-AFS)测定紫菜中的5种砷形态。紫菜样品都检测出了DMA(0.196～0.668 mg/kg),但没有检测出As(III),As(V),MMA和AsB,紫菜砷的形态主要是砷糖。     

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.     

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°.     

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.     

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