Differentiation of Belamcandae Rhizoma and Iridis Tectori Rhizoma by Thin-Layer Chromatography and High-Performance Liquid Chromatography

Objective:Belamcandae Rhizoma and Iridis Tectori Rhizoma are easily confused with each other.The main objective of this study is to distinguish them using chemical analysis.Materials and Methods:Thin-layer chromatography(TLC)and high-performance liquid chromatography(HPLC)fingerprint methods were established to compare the chemical profile,while HPLC quantitation was used to determine the contents of three isoflavones in thirty batches of Belamcandae Rhizoma and Iridis Tectori Rhizoma samples.Results:The two herbs could be distinguished by TLC using acetic acid-n hexane-ethyl acetate(1:90:80 v/v/v)as the mobile phase,according to the fluorescent band under 366 nm at R_(f) 0.2.In total,12 compounds were identified in the 24-min HPLC fingerprint.The similarity coefficient between the two herbs was 0.54±0.01.Mangiferin(1),tectoridin(2),iridin(3),irigenin(5),irisflorentin(6),and iristectorin A(9)were the main peaks in Belamcandae Rhizoma,while tectoridin(2)and tectorigenin(4)were the major peaks in Iridis Tectori Rhizoma.The contents of 2 in Iridis Tectori Rhizoma(2.50±0.20%)were 8.93 times higher than that of Belamcandae Rhizoma(0.28±0.08%),while the ones of 5 and 6 were slightly lower in Iridis Tectori Rhizoma.Conclusions:The study established fast and effective methods to distinguish Belamcandae Rhizoma from Iridis Tectori Rhizoma.

STUDY OF DERIVATIZATION OF PROTEIN WITH A EUROPIUM CHELATE AND APPLICATION TO HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

A europium chelate of 5-chlorosulfoyl-2- thenoyltrifluoroacetone(CTTA)was investigated for precolumn derivatization of protein for high performance liquid chromatography.This new label was highly fluorescent and suitable for time-resolved fluorometric detection.The detective limit of protein is less than 0.3ug in sample with a volume of 100ul.Theoretically,the new label can also be used in gel electrophoresis and protein blotting.

Determination of Tetracyclines in Honey Using Liquid Chromatography with Ultraviolet Absorbance Detection and Residue Confirmation by Mass Spectrometry

A determination method has been optimized and validated for the simultaneous analysis of tetracycline （TC）, oxytetracycline （OTC）, chlortetracycline （CTC） and doxycycline （DC） in honey. Tetracyclines （TCs） were removed from honey samples by chelation with metal ions bound to small Chelating Sepharose Fast Flow columns and eluted with Na2EDTA-Mcllvaine pH 4.0 buffers. Extracts were further cleaned up by Oasis HLB solid-phase extraction （SPE）, while other solid-phase extraction cartridges were compared. Chromatographic separation was achieved using a polar end-capped C 18 column with an isocratic mobile phase consisting of oxalic acid, acetonitrile and methanol. LC with ultraviolet absorbance at 355 nm resulted in the quantitation of all four tetracycline residues from honey samples fortified at 15, 50, and 100 ng/g, with liner ranges for tetracyclines of 0.05 to 2 μg/mL. Mean recoveries for tetracyclines were greater than 50% with R.S.D. values less than 10% （n= 18）. Detection limits of 5, 5, 10, 10 ng/g for oxytetracycline, tetracycline, chlortetracycline and doxycycline, respectively and quantitation limits of 15 ng/g for all the four tetracyclines were determined. Direct confirmation of the four residues in honey （2-50 ng/g） was realized by liquid chromatography-tandem mass spectrometry （LC/MS/MS）. The linear ranges of tetracyclines determined by LC/MS/MS were between 5 to 300 ng/mL, with the linear correlation coefficient r〉 0.995. The limits of detection of 1 to 2 ng/g were obtained for the analysis of the TCs in honey.

Assessment of Poultry Feed Contamination Level by Aflatoxin B1: Quantification by Two Chromatographic Analysis Methods

Aflatoxin B1 is a mycotoxin that can contaminate a wide feedstuffs variety. Ingestion of contaminated feed by poultry can lead to impaired health and zootechnical performances but also a human diet safety problem related to residues presence in animal origin products. Aflatoxin B1 contamination of poultry feed samples marketed in Dakar city and in peri-urban areas (Gorom, Sangalkam) was studied. A total of 15 samples were collected from Dakar city markets as well as from poultry farms in Gorom and Sangalkam areas. Aflatoxin B1 quantification was performed by high performance liquid chromatography and thin-layer chromatography. HPLC results showed that all samples were contaminated with levels ranging from 0.15 to 22 ppb, 0.099 to 2.05 ppb and 0.099 to 4.95 ppb respectively for Gorom, Sangalkam and Dakar. Only the finishing feed from Gorom had an aflatoxin B1 level above the maximum limit set by regulations. TLC is a suitable method for aflatoxins detection. However, it was associated with overestimation for aflatoxin B1 quantification. Results suggest that poultry feed represents a real source of human diet contamination. In addition, HPLC remains the most reliable quantification technique for quality control.

Development and Validation of a Liquid Chromatographic Method for the Determination of Leflunomide： Application to in vitro Drug Metal Interactions

Leflunomide is a leading drug for the treatment of rheumatoid arthritis. The principle aim of this study was to develop and validate an RP-HPLC method for the determination of leflunomide in bulk and pharmaceutical dosage form using diclofenac sodium as an internal standard. For this purpose, chromatography was accomplished on a Purospher Start, C18 （5 μm, 12.5 cm×0.46 cm） column at ambient temperature. Methanol ： water （80 ： 20, V/V） solvent system was selected as mobile phase, the pH of which was adjusted to 3.4 by ortho-phosphoric acid and de- livered at a flow rate of 1.2 mLomin-1. Seperation of leflunomide and diclofenac sodium was carried out on a Purospher Start, C18 equipped with a UV-visible detector at 248 nm. The suitability of the method for the quantita- tive determination of the drugs is proven by validation in accordance with the requirements laid down by the Inter- national Conference on Harmonization （ICH） guidelines. The method was accurate （99.55%--100.03%）, specific, linear （R2〉0.999） and precise （intra-day precision 0.023%--0.93% and inter-day precision 0.26%--0.944%） in the range of 0.5--20 μg·mL^-1. The minimum limit of detection and quantification in pharmaceutical formulation were 0.05 and 0.15 μg.mL^-1, respectively. Thus the proposed method is simple, accurate, reproducible and suitable for the routine analysis of leflunomide in pharmaceutical formulations and was applied to study in vitro drug-metal interactions.

金属有机框架富集-高效液相色谱法测定预包装果蔬制品中双酚A含量

目的:建立金属有机框架富集-高效液相色谱法测定预包装果蔬制品中双酚A的方法。方法:基于QuEChERS处理技术,通过优化提取和净化条件,利用金属有机框架材料富集果蔬样品中的双酚A,采用高效液相色谱法测定。结果:在优化条件下,双酚A在10~1000μg·L^(-1)具有良好的线性关系,相关系数(R^(2))大于0.9990,检出限为0.1μg·kg^(-1),定量限为0.3μg·kg^(-1)。不同果蔬基质的加标回收率在80.5%~105.2%,相对标准偏差为9.6%。不同果蔬基质效应对定量检测影响不显著(|ME|<10%)。结论:该方法灵敏度高,不需要内标和固相萃取装置,操作简便,可满足果蔬中双酚A的检测需求,为食品中双酚A的检测提供了一种经济、便捷的新思路。

β-环糊精金属有机骨架材料HPLC手性柱拆分噁唑禾草灵

合成了以β-环糊精和间羧基苯磺酰氯为有机配体、钾离子为配位离子的金属有机骨架材料(MOF)键合在高效液相色谱硅珠上,构建了高效液相色谱(HPLC)手性固定相(β-CD-MOF-P20@SiO_(2))新型材料,以此作为HPLC固定相,在反相色谱模式下,以乙酸铵-三乙胺/乙酸缓冲液和乙腈为流动相,优化流动相配比、缓冲液pH值、浓度和流速等色谱条件,获得了噁唑禾草灵两对映体最佳分离度,可达9.89。两对映体色谱峰响应信号与消旋体浓度在6.20×10^(-6)~2.99×10^(-4) mol/L范围内的线性相关性好(r=0.996 2~0.999 9),该MOF材料为噁唑禾草灵单一对映体定性、定量及制备提供了新方法。

锆基金属有机骨架复合材料用于海水中短裸甲藻毒素的固相萃取

短裸甲藻毒素(BTX-A)是由有害藻类短裸甲藻产生的次生代谢物,检测海水中的藻毒素可以预测赤潮的发生和增长。将BTX-A含量监测作为赤潮预警的因子之一可以有效提高赤潮预警的准确性,开发一种高效富集海水中BTX-A的样品前处理方法迫在眉睫。研究通过溶剂热法制备了具有较大比表面积(3109 m2/g)、对BTX-A有较强吸附作用的微米级Zr-MOFs复合材料(SiO_(2)@UiO-66),并将其作为固相萃取(SPE)填料,结合高效液相色谱-串联质谱(HPLC-MS/MS)技术,建立了一种检出限低(30 pg/mL)、线性范围宽(100~2000 pg/mL)、重复性良好(RSD≤85%,n=6)的海水中BTX-A的高灵敏检测方法。所建立的分析方法成功用于实际海水样品中BTX-A含量的分析和监测,结合福建省海洋与渔业局所发布的赤潮监测预警信息,可作为赤潮预警因子有效提高赤潮的监测和预警。

基于金属有机骨架多孔碳材料的分散固相萃取-超高效液相色谱-串联质谱法测定水中4种酚类内分泌干扰物

酚类内分泌干扰物是一种干扰内分泌系统的外源性物质,其进入生物体后会干扰细胞的正常功能,引起生殖发育毒性,因此亟需开发一种快速、灵敏的分析方法,用于环境水体中酚类内分泌干扰物的检测。本研究采用溶剂热法合成了一种由金属有机骨架衍生的多孔碳材料(UiO-66-C),并将其作为萃取吸附剂来富集水中的4种酚类内分泌干扰物(双酚A、4-叔辛基苯酚、4-壬基酚、壬基酚)。建立了一种分散固相萃取(DSPE)结合超高效液相色谱-串联质谱(UPLC-MS/MS)测定水中酚类内分泌干扰物的分析方法。通过扫描电子显微镜、X射线衍射及傅里叶变换红外光谱等测试方法对UiO-66-C进行表征,证明了该材料的成功制备。对DSPE条件进行优化,包括UiO-66-C用量、水样pH、吸附时间、洗脱液种类及体积、洗脱时间和离子强度。在最佳实验条件下,4种酚类内分泌干扰物在0.5~100μg/L范围内线性关系良好,方法检出限和定量限分别为0.01~0.13μg/L和0.03~0.42μg/L,日内和日间精密度分别为1.5%~10.6%和6.1%~13.2%。将该方法应用于自来水和地表水的检测,4种酚类内分泌干扰物的加标回收率为77.1%~116.6%;在自来水样品中未检测到4种酚类内分泌干扰物,而在地表水中检测到微量的4-壬基酚和壬基酚,检出水平分别为1.38μg/L和0.26μg/L。该方法具有良好的准确度和精密度,为环境水体中酚类内分泌干扰物的检测提供了一种快速、高效、灵敏的新途径。

基于金属有机骨架材料复合气凝胶的分散固相萃取-超高效液相色谱-串联质谱法测定水中7种苯氧羧酸类除草剂

苯氧羧酸类除草剂(PCAs)在水体中难以降解,对人类健康和生态环境造成严重威胁,因此亟需建立有效测定水体中痕量PCAs的方法。本文以常温干燥法制备的金属有机骨架/海藻酸钠气凝胶材料MIL-101(Fe)-NH 2/SA作为分散固相萃取的吸附剂,对环境水体中的7种PCAs进行吸附和富集,从萃取条件(气凝胶中MIL-101(Fe)-NH 2与海藻酸钠比例、水样pH、萃取时间)、洗脱条件(洗脱溶剂比例、洗脱时间、洗脱体积)、离子强度(盐度)等方面对萃取效果进行优化,以获得最佳的萃取效果。优化结果显示,吸附剂在12 min内可以对目标物进行完全吸附,用总体积为4 mL的含1.5%甲酸的甲醇洗脱30 s,目标物可以充分解吸。在最优条件下,结合超高效液相色谱-串联质谱法(UHPLC-MS/MS),建立了基于金属有机骨架复合气凝胶测定水体中7种PCAs的新方法。该方法可以呈现良好的线性关系(r^(2)≥0.9986),检出限和定量限分别为0.30~1.52 ng/L和1.00~5.00 ng/L。在低(8 ng/L)、中(80 ng/L)、高(800 ng/L)3个水平下进行精密度试验,日内和日间精密度(以RSD计)分别为6.5%~17.1%和7.4%~19.4%。该方法应用于地表水、海水、垃圾渗滤液的检测中,检出量为0.6~19.3 ng/L;在8、80、800 ng/L 3个水平下进行加标回收试验,回收率为61.7%~120.3%。该方法具有良好的灵敏度、精密度和准确度,为环境水体中苯氧羧酸类物质的痕量检测提供了一种新的检测方法。

水产品中甲基汞标准物质的研制

研制水产品中甲基汞标准物质。选用大鱿鱼脚作为候选物,经过洗涤、冻干、粉碎过筛、混样、装瓶等制样过程,每瓶按10 g分装,共制备300瓶。采用液相色谱-原子荧光法测定制备的标准物质中甲基汞含量,并进行均匀性和稳定性检验,由6家实验室采用同一检测方法协作定值,对定值结果的不确定度进行评定。研制的水产品中甲基汞参考标准物质中甲基汞的质量分数为0.164 mg/kg(以Hg计),扩展不确定度0.014 mg/kg(k=2),均匀性和稳定性良好,有效期为6个月。

金属螯合亲和色谱固定相合成及应用进展

金属螯合亲和色谱因具有高稳定、强金属螯合性能等优点,在重金属的检测与吸附、蛋白质的识别与鉴定、分离纯化中有着重要的研究价值。自金属螯合亲和色谱概念提出以来,该技术得到了极大的发展与应用。基于目前的研究文献报道,本文综述了金属螯合亲和色谱固定相合成及应用等方面的研究进展。

LC-MS在食品加工过程中重金属污染物检测中的应用

食品加工过程中出现的重金属污染问题严重威胁食品安全和公众健康。液相色谱-质谱联用技术因其高灵敏度、高选择性和多元素同时检测能力,被广泛应用于食品重金属检测。重金属污染的主要来源有原料污染、加工过程中的污染、包装材料和存储过程中的污染。液相色谱-质谱联用技术在水产品、蔬菜水果、谷物豆类检测的实际应用中展示出了高效、准确的检测能力。通过优化检测方法和降低成本,该技术将在食品安全监控中发挥越来越重要的作用,从而为保障消费者健康提供技术支持。

Selection of substrate recognition sequence of protein kinase with ferric chelation affinity chromatography

Protein kinase substrate phage (PKS phage) was constructed by fusing the substrate recognition consensus sequence of cAMP-dependent protein kinase (cAPK) with bacteriophage minor coat protein g3p and by dis-playing it on the surface of filamentous bacteriophage fd. Phosphorylation in vitro by cAPK showed a unique labelled band of approximately 60 ku, which was consistent with the molecular weight of the PKS-g3p fusion protein. Some weakly phosphorylated bands for both PKS phage and wild-type phage were also observed. Phage display random 15-mer peptide library phosphorylated by cAPK was selected with ferric (Fe3+ ) chelalion affinity resin. After 4 rounds of screening, phage clones were picked out to determine the displayed peptide sequences by DNA sequencing. The results showed that 5 of 14 sequenced phages displayed the cAPK recognition sequence motif (R)RXS/T. Their in vitro phosphorylation analyses revealed the specific labelled bands corresponding to the positive PKS phages with and without the typical (R)RXS/T sequence motif. It suggested that the new method of using ferric (Fe 3+ ) chelation affinity chromatography to identify the substrate specificity of protein kinase from random peptide library was feasible.

Determination of astaxanthin and astaxanthin esters in shrimp shell by HPLC

A method for determination of astaxanthin and astaxanthin eaters in shrimp shell by high performance liquid chromatography is established.Shrimp shell are addressed with 5%hydrochloric acid to remove calcium ions.After shell is dried,organics from shrimp shell are extracted with anhydrous ethanol.The alcohol extrative of the shrimp shell is mixed with the ammonium sulfate to extract astaxanthin by aqueous two-phase extraction.The crude astaxanthin is collected,which is distributed in the middle layer of the aqueous two-phase layer.After distilled water is added to the crude astaxanthin,the aqueous solution is centrifuged,and the previous step is repeated for several times.The precipitation in centrifuge tube is collected and dried.The crude astaxanthin dried is dissolved with acetone,and the sample solution is separated by TLC.Every pigment on the TLC plate is collected and dissolved with acetone.The pigments are determined by high performance liquid chromatograph.The results show that aqueous two-phase system,3 mL alcohol extractive of astaxanthin and 4.5 mL 20%ammonium sulfate,can be used to acquire crude astaxanthin.The wavelength of the maximum peak of astaxanthin in ethanol solution is 472 nm.A variety of pigments can be separated from the crude astaxanthin by thin-layer chromatography,including free astaxanthin,astaxanthin monoester,astaxanthin diester,echinenone and other substances.It can be seen from high performance liquid chromatography that the appearance time of free astaxanthin is from 4 min to 5.5 min,and the appearance time of astaxanthin monoester is from 10.5 min to 27.8 min.The method is simple about the sample pretreatment and feasible about the determination of astaxanthin and astaxanthin esters in shrimp shell.

重金属检测技术在水质分析中的应用

水质污染是当前环境领域的一大难题,尤其是由于工业化和城市化进程的加速,重金属污染引起了广泛关注。为了有效监测和控制水中重金属的浓度,各种先进的检测技术应运而生。本文首先介绍了水质中重金属常见的检测方法,如原子吸收光谱和荧光光谱,然后重点关注了近年来涌现的新型技术,包括电化学检测技术和生物检测技术。这些新技术不仅具有高灵敏度和选择性,而且具有实时监测和迅速响应的优势。

岭南常用中药材外源性污染物分析研究

目的研究岭南不同产地200批次10种常用中药材(巴戟天、化橘红、何首乌、砂仁、广藿香、南板蓝根、黑老虎、鸦胆子、槟榔、益智)中农药残留、重金属外源性污染物含量,以期为南药质量控制提供依据。方法按照2020年版《中华人民共和国药典》(简称《中国药典》)对10种岭南常用中药材中重金属及有害元素、农药等外源性污染物进行测定并分析测定结果。结果何首乌、南板蓝根、黑老虎、槟榔、益智中农药残留量及铅、砷、镉、汞、铜限量均符合《中国药典》的限量标准,巴戟天、化橘红、砂仁、鸦胆子均存在重金属不符合,广藿香存在农药残留量不符合。结论对于研究的品种,农药残留控制较好,需要重点监控铅、汞元素。

In vitro Safety Evaluation and Anticlastogenic Effect of BacoMind^(TM) on Human Lymphocytes

Objective BacoMind^TM （BM） is a standardized extract of Bacopa monnieri, which belongs to the family Scrophulariaceae and is a creeping annual plant found throughout the Indian subcontinent. It has been used by Ayurvedic medicinal practitioners in India for almost 3000 years and is classified as a medharasayana, a substance which improves memory and intellect. With the widespread traditional use as well as scientific validation of Bacopa monnieri for nootropic activity, a bioactive-rich unique phytochemical composition-BacoMind^TM was developed from B. monnieri for use as a cognition and memory enhancing agent. The present study aimed to investigate the in vitro toxicity of this formulation of BacoMind^TM on human lymphocytes and to rule out its possible contribution to mutagenicity. Methods In the present investigation the active ingredients present in BM were identified and quantified by high performance liquid chromatography （HPLC） and high performance thin-layer chromatography （HPTLC）. Antioxidant and anticlastogenic properties of BM were studied in vitro with and without metabolic activation. Doses of BM were chosen on the basis of mitotic index （MI） and cytokinesis-block proliferation index （CBPI）. Clastogenicity assays were performed at 31.2 μg/mL, 62.5 μg/mL, and 125 μg/mL, while the Salmonella reverse mutation assay （Ames test） was performed at doses of 61.72, 185.18, 555.55, 1666.67, and 5000.00 μg/plate. Results HPLC and HPTLC analysis of BM revealed the presence of bacoside A3. bacopaside Ⅰ, bacopaside Ⅱ, jujubogenin isomer of bacopasaponin C, bacosine, luteolin, apigenin, bacosine, and β-sitosterol D glucoside. BM demonstrated significant antioxidant activity. The number of chromosomal aberrations and the frequency of micronuclei induced by BM were not statistically significant up to a dose of 62.5 μg/mL. A subsequent dose of 125 μg/mL prior to metabolic activation induced mild clastogenicity, but it was found to be biologically insignificant as this effect was not seen post metabolic activation. BM also demonstrated a dose-dependent protection against the clastogens used in this study using the above tests for clastogenicity. Maximum protection was observed in presence of metabolic activation. Moreover, BM demonstrated no mutagenic effect on the tested strains, as observed in the Ames test. Conclusion BM protected human lymphocytes against various clastogens. BM also exhibited high antioxidant activity which might be responsible for the observed protective effects against the clastogens since the used clastogens are known to induce their clastogenic effects via production of oxidative radicals.

Qualitative Identification and Content Determination of Psoralen in Ficus Pandurata Hance

[Objectives]This study aimed to establish a qualitative identification and content determination method for psoralen in Ficus pandurata Hance and compare the psoralen contents in roots,stems and leaves of F.pandurate Hance and Ficus pandurata Hance var.holophylla Migo.[Methods]Thin-layer chromatography(TLC)was used for qualitative identification,and the content of psoralen was determined by high-performance liquid chromatography.The chromatographic conditions were as follows:column,Agilent ZORBAX Eclipse Plus C18(250 mm×4.6 mm,5μm);mobile phase,methanol-water(55∶45);flow rate,1 mL/min;detection wavelength,246 nm;column temperature,30℃;and injection volume,10μL.[Results]The TLC chromatogram of F.pandurate Hance showed clear spots and good separation.The concentration of psoralen detected in the range of 2.06-41.20μg/mL had a good linear relationship with the peak area(r=0.9999).The RSD values of the precision,stability and reproducibility tests were all less than 2%.The average recovery rate was 100.2%(RSD=1.13%,n=6).[Conclusions]The established method is simple,easy,accurate and reproducible.It can be used for quality control of F.pandurate Hance.

Quality Standard of Zijinbiao

[Objectives]To establish the quality standard for Zijinbiao.[Methods]Microscopic identification,physical and chemical identification,and thin-layer chromatography(TLC)were used to qualitatively identify Zijinbiao.The moisture,total ash,acid-insoluble ash,and alcohol-soluble extract content were determined.The content of Plumbagin was determined by high performance liquid chromatography(HPLC).[Results]Microscopic identification,physical and chemical identification and thin layer identification features were remarkable.The moisture,total ash,acid-insoluble ash,and extract content of the 15 batches of samples were 7.49%-11.84%,2.43%-5.81%,0.59%-3.18%and 13.80%-20.45%,respectively.The linear equation of Plumbagin was Y=38094X,R^(2)=0.9996.Plumbagin had a good linear relationship in the range of 0.01-0.53 mg/mL.[Conclusions]This method is specific and reproducible,and can be used for quality control of Zijinbiao.