微波消解火焰原子吸收光谱法连续测定金银花中铁、锌、铜和锰

采用微波消化技术,以氘灯背景校正方式,在HNO3介质中,直接用火焰原子吸收法在同一体系中连续测定了金银花中微量元素Fe、Zn、Cu、Mn,并优化了最佳实验条件.在选定条件下,检出限为Fe 0.0047 μg/mL,Zn 0.0032μg/mL,Cu 0.0052μg/mL,Mn 0.0028μg/mL,相对标准偏差为1.5%～3.2%,回收率为96.4%～103.4%.适用于金银花中微量Fe、Zn、Cu、Mn的测定.     

超声波提取-火焰原子吸收光谱法测定金银花中的Fe、Cu和Pb

建立了湿法和超声波提取处理样品,火焰原子吸收光谱法测定金银花湿法消解液及超声波提取液中Fe,Cu和Pb元素含量的方法.金银花中3种元素的含量Fe＞Cu＞Pb,硝酸作为提取剂,提取元素的溶出率的大小:Cu＞Pb＞Fe,回收率为85％-107％,RSD为0.6-1.0％.结果表明,超声波提取能较好地提取金银花中微量元素,元...     

高效液相色谱法测定金银花中保卫田残留量

本文用高效液相色谱法测定金银花保卫田残留量，使用ＯＤＳ柱，流动相２％，ＮＨ４Ａｃ－甲醇（６：４），流速１ｍＬ／ｍｉｎ柱温３０℃紫外检测器检测波长２８５ｎｍ，方法加标回收率８０．３％～８９．３％方法最低检出浓度０．０２μｇ／ｇ。     

Determination of chlorogenic acid by flow injection irreversible biamperometry

A flow injection irreversible biamperometric method for the determination of chlorogenic acid is described.The proposedmethod is based on the electrochemical oxidation of chlorogenic acid at pretreated platinum electrode and the reduction ofpermanganate at another electrode to form an irreversible biamperometric detection system.Under the external potential difference(△E)of 0 V,in the 0.05 mol/L sulfuric acid,chlorogenic acid can be determined over the range 0.8-120 mg/L with a samplemeasurement frequency of 80 samples/h.The detection limit is 0.18 mg/L.The proposed method exhibits the satisfactoryreproducibility with a relative standard derivation(R.S.D.)of 2.21%for 19 successive determinations of 40 mg/L.     

Geographical Discrimination of Honeysuckle (Lonicera japonica Thunb.) from China by Characterization of the Stable Isotope Ratio and Multielemental Analysis

A total of 117 honeysuckle (Lonicera japonica Thunb.) samples from four major regions of production in China, including Fengqiu in Henan, Pingyi in Shandong, Julu in Hebei, and Xiushan in Chongqing, were analyzed to determine their geographical origin. δ¹³C, δ¹⁵N, and δ¹⁸O values were determined by isotope ratio mass spectrometry (IRMS), and the contents of 18 elements (Fe, Mn, Cu, Zn, K, Ca, Mg, Pb, Cd, Cr, As, Hg, Se, Sr, Ni, Co, B, and Mo) were measured by inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). Multivariate statistical analysis by analysis of variance (ANOVA), principal component analysis (PCA), and linear discriminant analysis (LDA) were performed. The results showed that there were very significant differences in the stable isotope ratios and elemental concentrations in honeysuckle based on geographical origin, with plants from each region having a unique fingerprint. Discriminant functions were established to distinguish the origin of honeysuckle using suitable indicators including Cd, Cr, As, Hg, Se, Co, Ni, Sr, Fe, δ¹³C, δ¹⁵N, and δ¹⁸O. Cross-validated cases of 95.7% were correctly classified.     

Synthesis of Chlorogenic Acid Imprinted Chromatographic Packing by Surface-initiated Atom Transfer Radical Polymerization and Its Application

A novel chromatographic packing of chlorogenic acid（CGA） molecularly imprinted polymer（MIP） based on the 5.0 ~tm silica was prepared by surface initiated atom transfer radical polymerization（SI-ATRP） with 4-vinylpyridine（4-VP） as functional monomer, ethyl glycol dimethacrylate（EDMA） as cross-linker in the mixture of methanol and water（7：3, volume ratio） under mild reaction conditions. The characteristics of CGA MIP were investi- gated by elemental analysis, thermogravimetric analysis（TGA）, Fourier transform infrared spectrometry（FTIR） and atomic force microscopy（AFM）. The effects of some chromatographic conditions such as mobile phase composition and temperature on the retention time were investigated. The adsorption capacity of the stationary phase for com- pounds was determined by frontal chromatographic technique. The results show that Freundlich isotherm fits the ex- perimental adsorption isotherm data better than Langmuir model does. The relatively high heterogeneity index values regressed with the Freundlich isotherm suggest the formation of fairly homogeneous MIP. Thermodynamic data（AAH and AAS） obtained by van＇t Hoff plots reveal an entropy-controlled separation. The CGA MIP column was shown to be successful for the separation and purification of chlorogenic acid from the extract of Honeysuckle.     

金银花中多种金属元素的炭化酸溶法-ICP-AES研究

金银花为忍冬属植物, 是我国常用的传统珍贵药材,同时也是制作清凉饮料的重要原料,具有“清热解毒, 凉散风热”之功效。主治痈肿疗疮、喉痹、丹毒、热毒血痢、风热感冒、温病发热等症。文章介绍了采用炭化酸溶法进行消解, 用电感耦合等离子体原子发射光谱法同时测定试样中Cu, Mn, Ni, Pb, Fe, Cr, Ca和Mg等多种金属元素的方法。其检出限为0.002 4～0.049 2 μg·mL-1,变异系数1.1%～4.9%。元素的回收率为83.8%～115.6%。发现金银花中含有丰富的Ca, Mg, Fe和Mn含量相对较高。     

屋顶花园种植的金银花、竹荪中铅和镉含量及其评价

采用火焰原子吸收光谱法测定屋顶花园种植金银花、竹荪中Pb、Cd的含量。该法简单、快速、灵敏度高,准确性好。回收率在93.6%—96.7%之间,相对标准偏差小于5%。实验结果表明:金银花中Pb、Cd的平均含量范围分别为16.46—16.60、0.19—0.23mg/kg,竹荪中Pb、Cd的平均含量范围分别为11.07—14.62、5.54—5.48mg/kg。