高效液相色谱测定海虾中呋喃唑酮残留量

样品用二氯甲烷提取,正己烷纯化、外标法定量,高效液相色谱(HPLC)法检测海虾中呋喃唑酮残留量.本方法校准曲线线性范围为0.01-1.00μg/mL,r=0.9991.检测下限为1.0μg/kg,回收率92.0%-100.5%,相对标准偏差(RSD)为2.9%-4.6%.测定方法准确,灵敏,达到了水产品检测的要求.     

FAAS法测定硫酸中的铜、铁和锌

采用火焰原子吸收光谱法测定硫酸中铜、铁和锌,确定了最佳仪器工作条件和样品处理方法.在选择好的实验条件下,测定铜的特征浓度为0.005μg/mL/1%;铁的特征浓度为0.014μg/mL/1%吸收;锌的特征浓度为0.002μg/mL/1%吸收.回收率分别为铜97.7%-98.2%,铁98.2%-99.4%,锌96.8%-98.7%.     

FAAS测定电解镉中的Zn、Cu和Fe

采用火焰原子吸收光谱法测定电解镉中铜、铁和锌的方法,确定了最佳仪器工作条件和样品处理方法.在选择好的实验条件下.测定铜的特征浓度为0.006#g/mL/1%吸收;铁的特征浓度为0.015μg/mL/1%吸收;锌的特征浓度为0.0031μg/mL/1%吸收.回收率分别为铜97.5%-98.0%,铁99.1%-100.2%,锌97.4%-99.1%.     

微波消解-氢化物发生原子荧光光谱法测定土壤中砷和硒

采用王水(1 1)作消解剂,以微波消解的方法处理土壤样品,氢化物发生-原子荧光光谱法测定土壤中砷、硒,设定了最佳的样品处理条件和仪器测定条件.利用加标回收试验,对分析方法进行了验证.砷、硒的检出限分别为0.94μg/L和0.15μg/L,测定土壤中砷、硒的回收率分别为90%-105%、89%-104%,RSD分别为2.2%-4.0%、1.9%-3.1%.     

液相色谱法检测化妆品中3种防腐剂

建立了化妆品中防腐剂水杨酸、苯甲酸和山梨酸的高效液相色谱检测方法.试样经乙醇和硫酸处理后,由C18反相色谱柱进行分离,紫外检测器进行检测,用外标法定量.实验结果表明,该方法简便、高效,测定结果准确,适用于化妆品中水杨酸、苯甲酸和山梨酸含量的同时检测.     

柱前衍生-反相高效液相色谱法快速测定食品中的甜蜜素

样品溶于水,在酸性条件下,以次氯酸钠柱前衍生。在C18柱上用乙腈:水(体积比为70:30)为流动相,在314nm处测定,外标法反相高效液相色谱法快速测定食品中的甜蜜素,加标回收率为96.1%-101.8%之间,食品中共存的苯甲酸、山梨酸、安赛蜜、色素等不影响测定,方法简捷、准确。     

RP-HPLC同时测定饮料中安赛蜜、阿斯巴甜及苯甲酸

建立了一种同时检测几种饮料中安赛蜜、阿斯巴甜及苯甲酸的高效液相色谱检测方法。确定了最佳色谱条件:色谱柱:Diamonsil-C₁₈（250mm×4.6mm,5μm）;流动相:0.02mol/L硫酸铵:乙腈:磷酸=80:20:0.02（V/V/V）;流速:1.0mL/min;紫外检测器检测波长:210nm。该方法加标回收率在94.5%—101.5%之间,精密度小于3%。实现了对碳酸饮料、茶饮料及橙汁中的安赛蜜、阿斯巴甜及苯甲酸的同时测定。     

FAAS法测定硫酸中的铁和锌

本文建立了火焰原子吸收光谱法测定硫酸中铁和锌的方法，确定了最佳仪器工作条件和样品处理方法。在选择好的实验条件下，测定铁的特征浓度为0.014μg/mL/1%吸收；测定锌的特征浓度为0.002μg/mL/1%吸收。回收率分别为铁98.8%-103.4%，锌92.5%-98.6%。     

固相萃取-TXRF测定高冰镍中的贵金属

制备了以Dowex1-X10阴离子交换树脂为填料的固相萃取小柱,建立了固相萃取、全反射X射线荧光分析法(TXRF)测定高冰镍中微量贵金属钯、铱、铂和金含量的新方法,解决了复杂体系中微量贵金属检测前的分离富集难的问题.在0.5mol/L盐酸体系中,TXRF测定高冰镍中钯、铱、铂和金的相对标准偏差(RSD)均小于3.4％,其仪器检出限分别为0.015、0.011、0.013μg/mL和0.01 5μg/mL,方法检出限分别为0.050、0.036、0.043μg/g和0.050μg/g.实际样品的测定结果与ICP-MS基本一致.用TXRF可以同时、快速地测定高冰镍中的贵金属,样品测定结果可靠.     

高效液相色谱法测定余甘子中单宁酸的含量

建立了高效液相色谱法测定余甘子中单宁酸含量的方法,采用Hypersil ODS(125×4.0 mm,5μm)色谱柱;检测波长275nm;流动相为80%甲醇和20%水;流速为0.5mL·min-1.可在3min内完成一次样品分析.所测单宁酸在120-240 ng/mL的范围内有良好的线性关系.相关系数达99.996%以上,加标回收率在99.7%-107.5%之间.本法快速,方便,精确可靠.     

油酸和亚油酸的激光拉曼光谱

不同的不饱和脂肪酸各自具有其不同的生理功能,但常见的不饱和脂肪酸产品大部分为几种脂肪酸的混合物,故在应用前对不纯的脂肪酸产品进行组成分析是必须的。测量了不饱和脂肪酸产品组分中最常见的油酸和亚油酸的拉曼光谱,确定了各拉曼谱线的振动模归属,分析了其分子的构象特征。该结果为研究长链不饱和脂肪酸的振动能级结构及能级间跃迁等做了基础工作,丰富了有机物分子的价键数据和性质。同时详细分析比较了油酸和亚油酸拉曼光谱的差异,为定性鉴别脂肪酸产品的成分提供了一种简便有效的方法,对拉曼光谱在地沟油检测方面的应用具有重要的指导意义。     

Near UV Spectra of Phenoxyacetic Acid and Phenoxypropanoic Acid

Abstract

The secondary transition of the benzene molecule lies towards 250-260 nm. It is electronically forbidden because of the D_6h symmetry of the molecule. The intensity of the transition is low (?_max = 220; medium : cyclohexane) and very sensitive to interactions with the surrounding parts of the molecule likely to perturb the symmetry. Substituents distort all the more the symmetry as their orbitals couple with the orbitals of the x system. They increase the intensity of the transition according to a vector scheme taking into account the positions of the substituents around the nucleus, and the strength of their coupling (SKLAR). ^7-14It has been shown that the too much qualitative SKLAR's approach could be superseded by the much more quantitative and more accurate NVM (New Vector Model) l5 grounded on MNDO calculations, or the IVM (Interaction Vector Model) using a more empiric approach.     

Biophysical Properties of Phenyl Succinic Acid Derivatised Hyaluronic Acid

Modification of hyaluronic acid (HA) with aryl succinic anhydrides results in new biomedical properties of HA as compared to non-modified HA, such as more efficient skin penetration, stronger binding to the skin, and the ability to blend with hydrophobic materials. In the present study, hyaluronic acid has been derivatised with the anhydride form of phenyl succinic acid (PheSA). The fluorescence of PheSA was efficiently quenched by the HA matrix. HA also acted as a singlet oxygen scavenger. Fluorescence lifetime(s) of PheSA in solution and when attached to the HA matrix has been monitored with ps resolved streak camera technology. Structural and fluorescence properties changes induced on HA-PheSA due to the presence of singlet oxygen were monitored using static light scattering (SLS), steady state fluorescence and ps time resolved fluorescence studies. SLS studies provided insight into the depolymerisation kinetics of PheSA derivatised HA matrix in the presence of singlet oxygen. Time resolved fluorescence studies grave insight into the dynamics of the reaction mechanisms induced on HA-PheSA by singlet oxygen. These studies provided insight into the medical relevance of PheSA derivatised HA: its capacity of scavenging singlet oxygen and of quenching PheSA fluorescence. These studies revealed that HA-PheSA is a strong quencher of electronic excited state PheSA and acts as a scavenger of singlet oxygen, thus medical applications of this derivatised form of HA may protect tissues and organs, such as skin, against reactive oxygen species damage.     

磺基水杨酸分光光度法测定药物中的抗坏血酸

本文基于抗坏血酸将Ｆｅ３＋还原为Ｆｅ２＋,用磺基水杨酸作Ｆｅ３＋的显色剂,籍退色光度法测定了药物中的抗坏血酸。     

系数倍率紫外光谱法同时测定复方苯甲酸软膏中的苯甲酸和水杨酸的研究

本文用系数倍率紫外光谱法同时测定了复方苯甲酸软膏中苯甲酸和水杨酸的含量,取得了满意的结果,苯甲酸测定回收率为99．33％－101．80％,水杨酸测定回收率100．92％－105．46％。     

Gallic Acid,Ellagic Acid and Pyrogallol Reaction with Metallic Iron

Hyperfine Interactions - The reaction between gallic acid, ellagic acid and pyrogallol with metallic iron was studied using infrared and Mössbauer spectroscopy. Most hydrolysable tannins with...     

高效液相色谱法测定春根藤中的齐墩果酸和熊果酸

采用超声辅助提取,建立春根藤中齐墩果酸和熊果酸的高效液相色谱的分析方法。采用Kromasil C₁₈柱（4.6mm×250mm,5μm）色谱柱,以甲醇:水:磷酸（90:10:0.1,V/V/V）为流动相,流速1.0mL·min^-1,检测波长210nm,柱温30℃。齐墩果酸和熊果酸进样量分别在0.484—4.84μg（r=0.9999）和0.664—6.64μg（r=0.9998）范围内与峰面积呈良好的线性关系,平均加标回收率（n=6）分别为97.5%和96.9%,RSD分别为1.5%和1.4%。该方法简便、准确、可靠,可用于春根藤中齐墩果酸和熊果酸含量的测定。     

Dual Wavelength Spectrophotometry. Determination of 1,2,4-Benzenetricarboxylic Acid and Benzenepentacarboxylic Acid

Dual wavelength ultraviolet spectrophotometry was utilized for the determination of 1,2,4-benzenetricarboxylic and benzenepentacarboxylic acids in their simultaneous solution.     

高效液相色谱法测定三姐妹中的齐墩果酸和熊果酸

应用高效液相色谱法同时测定三姐妹中齐墩果酸和熊果酸两种三萜酸类成分的含量.采用Kromasil C18色谱柱(4.6mm×250mm,5μm),以甲醇∶水∶磷酸(90:10∶0.1,V/V/V)为流动相,流速1.0mL·min-1,紫外检测波长210nm,柱温30℃.齐墩果酸进样量在0.684-6.84μg时,与峰面积呈良好的线性关系(r=0.9999),平均回收率为98.3％,RSD为1.9％(n=5);熊果酸进样量在1.064-10.64μg时,与峰面积呈良好的线性关系(r=0.9998),平均回收率为97.2％,RSD为2.4％(n=5).方法准确,操作简便,数据可靠,可用于三姐妹中齐墩果酸和熊果酸的含量测定.     

RP-HPLC-ELSD法测定连翘中齐墩果酸及熊果酸的含量

采用反相高效液相色谱-蒸发光散射检测器(RP-HPLC-ELSD)测定连翘中齐墩果酸及熊果酸的含量。色谱柱为Kromasil C_(18)(200mm×4.6mm,5μm),流动相为甲醇-水(体积比为90:10),流速0.8mL·min~(-1),柱温为室温,漂移管温度85℃,气体流量2.30L·min~(-1),撞击器:关。齐墩果酸进样量在0.46—2.30μg(r=0.9995),熊果酸进样量在0.30—1.50μg(r=0.9994)时呈良好的线性关系,平均加样回收率分别为96.11%和94.84%,相对标准偏差分别为1.98%和1.83%。RP-HPLC-ELSD法具有准确度高,简便快捷,干扰少,重现性好的优点,可用于连翘药材的质量控制。