极谱催化波法测定马蔺子素

报道了在Na2 B4 O7 KH2 PO4 K2 S2 O8体系中马蔺子素的极谱催化波。拟定了测定马蔺子素的新方法。在 8.0× 10 - 3mol/LNa2 B4 O7 1.6× 10 - 2 mol/LKH2 PO4 (pH =7.7) 5 .0× 10 - 3mol/LK2 S2 O8底液中 ,极谱催化波峰电位Ep=-1.2 3V(vs .SCE) ;二阶导数峰峰电流i″p 与马蔺子素浓度在 2 .0× 10 - 9～ 2 .0× 10 - 6 mol/L范围内呈良好线性关系 ,检出限为 1.0× 10 - 9mol/L。催化波灵敏度比相应马蔺子素还原波高 75倍。采用该法测定了胶囊中马蔺子素的含量     

极谱催化波法测定土霉素

H2 O2 存在时 ,产生土霉素的极谱催化波 ,该催化波的灵敏度比相应土霉素的还原波高 8倍 ,据此拟定了测定土霉素的新方法。在 0 .1 0mol LKH2 PO4 Na2 HPO4(pH 7.4± 0 .2 ) - 1 .6× 1 0 -3 mol LH2 O2 底液中 ,催化波峰电流与土霉素浓度在 5 .0× 1 0 -7～ 9.0× 1 0 -6mol L范围内呈线性关系 (n =1 0 ,r=0 9996)。检出限为 1 .0× 1 0 -7mol L。     

极谱催化波法测定黄连素

基于黄连素在过氧化氢存在下产生的极谱催化波,拟定了测定黄连素的新方法。在８．０×１０－２ｍｏｌ／ＬＮａ２Ｂ４Ｏ７－Ｎａ２ＣＯ３（ｐＨ９．４±０．４）－４．０×１０－３ｍｏｌ／ＬＨ２Ｏ２底液中,催化波峰电流与黄连素浓度在 １．０ × １０－８～ ３．０ × １０－７ｍｏｌ／Ｌ范围内呈线性关系。催化波的灵敏度比相应黄连素还原波高２５倍。     

极谱催化波法测定地塞米松

基于地塞米松在过硫酸钾存在下产生的极谱催化波 ,拟定了测定地塞米松的新方法。与基于还原波的差分脉冲极谱法相比 ,本方法用线性变位极谱法获得的分析灵敏度提高了两个数量级。在 2 .0× 10 - 3mol LH2 SO4 ～ 2 .0× 10 - 2 mol LK2 S2 O8底液中 ,地塞米松于 - 1 0 8V (vs .SCE)处产生一极谱催化波 ,其二阶导数峰电流与地塞米松浓度在 3.2× 10 - 8～ 3.2× 10 - 7mol L范围内呈线性关系 (r =0 .9994 ,n =6 ) ,检出限为 1.0×10 - 8mol L。讨论了极谱催化波产生的机理。     

碘酸钾存在下极谱催化波法测定陈皮甙

基于陈皮甙在ＫＩＯ３存在下产生的极谱催化波，拟定了测定陈皮甙的新方法。在 ０．５５ ｍｏｌ／Ｌ ＨＡｃ－０．０１ｍｏｌ／Ｌ　ＮａＡｃ（ｐＨ ４．００±０．０５）－１．０×１０～（－３）ｍｏｌ／Ｌ ＫＩＯ３缓冲溶液中，陈皮甙催化波的峰电位为－１．３５ Ｖ（ｖｓ，ＳＣＥ），它的一阶导数峰峰电流与陈皮甙浓度在２．６ × １０～（－７）～２．６ × １０～（－６）ｍｏｌ／Ｌ范围内呈线性关系（ｒ＝０．９９７０，ｎ＝６）。本方法比现有的电化学方法灵敏度高一个数量级。可用于直接测定中草药贯众水提液中陈皮甙含量。     

锗—芦丁极谱络合吸附波的研究

在醋酸盐缓冲底液中，可获得Ｇｅ－芦丁的２个灵敏的络合吸附波Ｐ１和Ｐ２，分别对应于络合物中Ｇｅ（Ⅳ）还原至Ｇｅ（Ⅱ）再还原至Ｇｅ（０）。两波的检出限分别为８．０×１０＾－８和４．０×１０＾－８ｍｏｌ／Ｌ。测得电活性络合物的组成为Ｇｅ：Ｒｔ＝１：３，表面电极反应的速率常数（ｋｓ）１＝１０．５ ｓ＾－１，（ｋｓ）２＝１．９ｓ＾－１。还测定了有机锗口服液中锗的含量。     

过硫酸钾存在下极谱催化波法测定芬布芬

过硫酸钾存在下极谱催化波法测定芬布芬;芬布芬;过硫酸盐;平行催化波;线性扫描极谱法     

极谱催化波法测定苯甲醛

在磷酸盐缓冲溶液中 ,苯甲醛与联氨反应生成的产物苯甲醛腙在K2 S2 O8存在时于 - 1.2 2V(vs.SCE)产生一灵敏的极谱催化波。基于此 ,拟定了测定痕量苯甲醛的新方法。在 8.0× 10 -2 mol/LKH2 PO4 NaOH(pH 8.0± 0 .2 ) 2 .5× 10 -2 mol/L联氨 - 3.5× 10 -2 mol/LK2 S2 O8底液中 ,极谱催化波峰电流与苯甲醛浓度在 1.0× 10 -9～ 6 .2× 10 -8mol/L范围内呈线性关系 ,比无K2 S2 O8存在时灵敏度提高约 6 0倍。本方法适用于生活污水中苯甲醛含量的测定     

A new type of polarographic catalytic wave of organic compound——Studies on the polarographic catalytic wave of medroprogesterone acetate in the presence of KIO_3

The polarographic behavior and catalytic wave mechanism of medroprogesterone acetate (MPA) were studied in both aqueous and DMF media. In 0.2 mol/L acetic acid-sodium acetate (pH 5.0) buffer solution, the C=C bond of MPA first undergoes le, lH~ reduction to form protonated free radical HMPA(?), the further reduction of HMPA(?) in le, 1H~ process is simultaneous with the dimerization reaction between HMPA(?) and neutral molecular MPA. In DMF media containing 0.1 mol/L tetrabutylammonium tetrafluoborate (TBA·BF_4), the C=C bond of MPA shows two le, 1H~ reduction waves, which are ascribed to the reduction of MPA and free radical MPA, respectively. Here, no dimerization reaction occurs. These processes produce the reduction wave of MPA. In the presence of oxidant KIO_3, a polarographic catalytic wave of MPA is observable due to a chemical reaction between HMPA(?) or MPA(?) and KIO_3 as well as its intermediate species to regenerate MPA. The catalytic wave, which is caused by the reduction of organic com     

过硫酸钾存在下曲匹布通极谱平行催化波的研究及其应用

采用平行催化波法、循环伏安法等手段研究了在KH2PO4-Na2HPO4介质中过二硫酸钾存在下曲匹布通平行催化波产生的机理。曲匹布通的羰基官能团C=O在KH2PO4-Na2HPO4介质中以2e-,2H+方式极谱还原,产生了单个还原波。加入氧化剂过二硫酸钾时,曲匹布通还原中间体自由基在电极表面上能被过二硫酸钾及其中间还原体硫酸根阴离子自由基氧化,再生为原可还原基团C=O,从而产生了曲匹布通的平行催化波。基于此,提出了一种测定曲匹布通的新方法。     

A new type of polarographic catalytic wave of organic compound

The polamgraphic behavior and catalytic wave mechanism of medroprogestemne acetate (MPA) were studied in both aqueous and DMF media. In 0.2 mol/L acetic acid-sodium acetate (pH 5.0) buffer solution, the bond of MPA first undergoes le, lH⁺ reduction to form protonated free radical HMPA, the further reduction of HMPA in le,1H⁺ process is simultaneous with the dimerization reaction between HMPA and neutral molecular MPA. In DMF media containing 0.1 mol/L tetrabutylammonium tetrafluoborate (TBA.BF₄), the bond of MPA shows two le, 1H⁺reduction waves, which are ascribed to the reduction of MPA and free radical MPA.^-, respectively. Here, no dimerization reaction occurs. These processes produce the reduction wave of MPA. In the presence of oxidant KIO₃,a polamgraphic catalytic wave of MPA is observable due to a chemical reaction between HMPA. or MPA.^- and KIO₃ as well as its intermediate species to regenerate MPA. The catalytic wave, which is caused by the reduction of organic compound itself and the chemical reaction between oxidant and organic intermediate free radical to regenerate original organic compound, is a new-type wave of organic compound. Under optimum experimental conditions, the sensitivity of MPA catalytic wave in the presence of KIO₃ is an order of magnitude higher than that of its reduction wave. The catalytic wave can be used for analytical purpose. The calculated rate constant of catalytic reaction is 1.7 × 10³ mol·L^-1·s^-1. Project supported by the National Natural Science Foundation of China (Grant No. 29875017).     

Polarographic catalytic wave of hydrogen——Parallel catalytic hydrogen wave of bovine serum albumin in the presence of oxidants

A polarographic catalytic hydrogen wave of bovine serum albumin (BSA) at about -1.80 V (vs. SCE) in NH4CI-NH3 · H2O buffer is further catalyzed by such oxidants as iodate, per-sulfate and hydrogen peroxide, producing a kinetic wave. Studies show that the kinetic wave is a parallel catalytic wave of hydrogen, which resulted from that hydrogen ion is electrochemically reduced and chemically regenerated through oxidation of its reduction product, atomic hydrogen, by oxidants mentioned above. It is a new type of poralographic catalytic wave of protein, which is suggested to be named as a parallel catalytic hydrogen wave.     

Polarographic catalytic wave of hydrogen

A polarographic catalytic hydrogen wave of bovine serum albumin (BSA) at about-1.80 V (vs. SCE) in NH₄Cl-NH₃ · H₂O buffer is further catalyzed by such oxidants as iodate, persulfate and hydrogen peroxide, producing a kinetic wave. Studies show that the kinetic wave is a parallel catalytic wave of hydrogen, which resulted from that hydrogen ion is electrochemically reduced and chemically regenerated through oxidation of its reduction product, atomic hydrogen, by oxidants mentioned above. It is a new type of poralographic catalytic wave of protein, which is suggested to be named as a parallel catalytic hydrogen wave.     

Differentiation of herbs linked to "Chinese herb nephropathy" from the liquid chromatographic determination of aristolochic acids

A HPLC method was developed and applied to analyze aristolochic acids (AA-I and AA-II) in Chinese medicinal herbs. The herb samples were extracted by using ultrasonication with the extraction efficiency of better than 82%. Extracts were then filtered and injected onto a C18 column eluting under a gradient program using methanol and water-containing 0.5% acetic acid. The method with the detection limits of 1.33 ng for AA-I and 7.29 ng for AA-II per injection was successfully applied for the analysis of traditional Chinese medicine (TCM) and related products and differentiation of Chinese medicinal herbs that have previously been misused and caused toxicological effects. The developed protocol provided an example that analysis of selected component markers could serve for health security and quality control of TCM consumption.     

Determination of ruscogenin in crude Chinese medicines and biological samples by immunoassay

Ruscogenin is a major bioactive steroidal aglycone found in the Chinese medicine, Ophiopogon japonicus. We have developed a quantitative determination of ruscogenin with an indirect enzyme-linked immunosorbent (ELISA) assay using polyclonal antibodies against ruscogenin conjugated with bovine serum albumin. This assay was highly sensitive, and it had considerably less cross-reactivity to diosgenin and sarsasapogenin, but high cross-reactivity to ruscogenin glycosides. The assay was successfully used for the measurement of ruscogenin concentrations in crude Chinese medicines and in biological samples from a pharmacokinetics study of ruscogenin.     

原子吸收法测定中草药中钙、镁、铁、锌、铜和锰

钙、镁、铁、锌、铜、锰都是人体必不可少的元素 ,而中草药中这些元素的测定 ,无论是从中医药学还是营养卫生学的角度而言 ,都显得极其重要和必不可少[1 ,2 ] 。本文采用原子吸收分光光度法连续测定中草药中的钙、镁、铁、锌、铜、锰。1　实验部分1 .1　仪器与试剂Ｚ 80 0 0偏振塞曼原子吸收分光光度计 ,配火焰和石墨炉原子化器 (日本日立公司 )。ＬａＣｌ3溶液( 1 0 0ｇ/Ｌ) ;ＳｒＣｌ2 溶液 ( 5 0ｇ/Ｌ) ;钙、镁、铁、锌、铜、锰混合标准储备液 (Ｃａ、Ｍｇ、Ｆｅ 2ｇ/Ｌ ,Ｍｎ 1ｇ/Ｌ ,Ｚｎ、Ｃｕ 0 5ｇ/Ｌ)。1 .2　样品液的制备准确称…