Quality Evaluation of Leontopodium franchetii Beauv. from Different Localities Based on Moisture,Ash and Extract Contents and Thin-layer Chromatography

[Objectives] The aim was to determine the moisture,ash and extract contents in Leontopodium franchetii Beauv. from different localities. [Methods] The contents of moisture,total ash,acid-insoluble ash and extract in L. franchetii from different localities were determined according to the methods described in Chinese Pharmacopoeia( 2015 Edition). [Results] In the 10 samples,the contents of moisture were all less than or equal to 15. 0%; the contents of total ash were all below 12. 0%; and the contents of acid-insoluble ash were all less than 3. 0%. The contents of water-soluble extract( by cold-soaked extraction method) in the samples were all below 12. 0% except those from Hongyuan Prairie of Sichuan Province and Xinglong Mountain in Lanzhou City,Gansu Province. [Conclusions]The contents of the four indicators measured in this experiment varied by small margins,indicating that the quality was relatively stable. This study provides theoretical data for the revision of the quality standards for L. franchetii.

Separation of Amino Acids Based on Thin-Layer Chromatography by a Novel Quinazoline Based Anti-Microbial Agent

A newly designed quinazoline based compound, 6-pyridin-2-yl-5,6-dihydro-benzo[4,5]imidazo[1,2-c] quinazoline (PDBIQ) has shown the ability for the easy detection of nineteen amino acids on thin-layer chromatography plates as a spray reagent. This new reagent enabled to produce various distinguishable colors with amino acids with different RF values. The detection limits and the binding ability of PDBIQ with amino acids have been calculated. PDBIQ is also able to detect aminoacids from hydrolised seed protein. The title compound also exhibited profound inhibitory action against some gm (+ve) and gm (-ve) bacterial organisms. This paper deals with synthesis, spectroscopic application and biological evaluation of the organic moity.

ANALYSIS OF HUMAN PLACENTA BY ^(31)P NUCLEAR MAGNETIC RESONANCE AND THIN-LAYER CHROMATOGRAPHY SCANNING COMBINED WITH THE CORRECTIVE METHOD OF ABSORBANCE PROPORTIONAL COEFFICIENT

Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance proportional coefficient. The NMR spectrometer used this investigation was a Bruker AM-500 spectrometer operating at 202.4 MHz for ^(31)P chemical shifts are relative to 85% phosphoric acid. TIC was carried out by silica gel H plate developed in chloroform-methanol-glacial acetic acid-ethanol-water(25:4:6:2:0.5),with Vaskovsky reagent as colour -developing agent of phospholipids.

基于硅胶腕带被动采样/气相色谱-质谱法的大学生群体合成麝香暴露监测研究

合成麝香(SMs)是日常洗护用品中广泛使用的香精添加剂,对人体的长期暴露具有潜在健康风险。该研究采用硅胶腕带作为被动采样器采集大学生人群日常接触的SMs,经乙酸乙酯溶液浸提后通过固相萃取(SPE)富集,利用气相色谱-质谱联用技术(GC-MS)和内标法检测个体样品中SMs的暴露浓度,并通过危险商(HQ)评估SMs暴露的健康风险。结果表明,佳乐麝香(HHCB)和吐纳麝香(AHTN)在5~500μg/L范围内线性关系良好,相关系数(r^(2))均大于0.999,检出限为1.2~6.6μg/L,定量下限为4.10~21.9μg/L。HHCB和AHTN的加标回收率分别为91.6%~113%和92.7%~118%,相对标准偏差(RSD)分别为1.9%~15%和0.81%~11%。在大学生人群中,HHCB和AHTN的每日暴露量分别为2.60μg(/kg·d)和0.23μg(/kg·d)。SMs皮肤暴露的危险商(HQderm)小于1,尚不会对大学生群体产生人体健康风险。硅胶腕带可作为化学品人体皮肤暴露的被动采样器,为化学暴露与人体健康风险评估研究提供数据和新方法。

智能电子产品典型材料中7种二甲基环硅氧烷含量的测定

智能电子产品中残留的二甲基环硅氧烷(DMCs)可能随设备报废而进入环境。该研究针对智能电子产品材料基质复杂且溶解性和分散性差的特点,选取硅橡胶、胶黏剂和塑料3种典型材料为代表,采用丙酮对颗粒度为0.5 cm×0.5 cm的样品进行超声萃取,选择SH-Rxi-5Sil MS毛细管柱(30 m×0.25 mm×0.25µm)进行气相色谱-质谱(GC-MS)分离,通过特征碎片离子实现了7种DMCs(D3、D4、D5、D6、D7、D8、D9)的定性定量分析。7种DMCs在0.1~10.0 mg/L质量浓度范围内呈良好的线性关系(r^(2)≥0.9993),方法定量下限为0.5µg/g;7种DMCs在智能电子产品3种典型材料中的平均加标回收率为83.8%~105%,相对标准偏差(RSD,n=6)为1.5%~4.6%。将该方法用于7种不同智能电子产品材料中DMCs的分布分析,结果在6个样品中检出DMCs,总含量为30.0~1.6×10^(3)µg/g。

Bio-screening and quantification of methyl paraben in vinegar and coconut juice separated by HPTLC

As a widely used food preservative,methyl paraben was experimentally evidenced with serious hormonelike adverse effects.Herein,a high performance thin-layer chromatography platformed bioluminescent bioautography and image analysis for the selective quantification and confirmation of methyl paraben was proposed and validated in vinegar and coconut juice.First,the detectability of the bioautography to the analyte on different layer materials was estimated,revealing that normal silica gel was the best choice.After that,the liquid of sample extract and working solution were separated to overcome the background noises due to co-extracted matrices.The separation result was then coupled to the optimized bioautography,enabling instant and straightforward screening of the targeted conpound.For accurate quantification,bioluninescent inhibition pattern caused by the analyte was processed by image analysis,giving useful sensitivity(LOD>16 mg/kg),precision(RSD<10.1%)and accuracy(spike-recovery rate 76.9%-112.2%).Finally,the suspected result was confirmed by determining its MS fingerprint,further strengthening the reliability of screening.

TLC Identification and Extraction Process of Rubiasin-1-methyl Ether from Yao Medicine Chuanlianzhu

[Objectives]To establish a thin-layer chromatography(TLC)method for the determination of rubiadin-1-methyl ether in Yao Medicine Chuanlianzhu(Damnacanthus giganteus).[Methods]A silica gel G thin-layer plate was adopted for TLC.Petroleum ether(60-90℃)-chloroform-methanol-water(7:15:3:1)was used as the developing solvent and inspected under ultraviolet lamp(365 nm).The content was determined by Inertsil ODS-3 C 18 column(4.60 mm×250 mm,5μm),mobile phase:acetonitrile-0.2%phosphoric acid gradient elution,detection wavelength 277 nm,flow rate 1.0 mL/min,column temperature 30℃,injection volume 10μL.[Results]The spots of 10 Chuanlianzhu samples from different origins showed the same color at the same position as the control,and the spots were clear and specific.The injection volume of rubiadin-1-methyl ether showed a good linear relationship in the range of 2.90-145μg(R=0.9996).The average recovery rate of rubiadin-1-methyl ether in the low,medium and high dose groups of Yao Medicine Chuanlianzhu was 98.72%,and RSD=1.78%.[Conclusions]This method can effectively identify Yao Medicine Chuanlianzhu medicinal materials and accurately determine the content of rubiadin-1-methyl ether in the medicinal materials.It provides a scientific basis for the development and utilization of Yao Medicine Chuanlianzhu medicinal resources.

工作场所空气中乙醇胺的测定方法

文章以硅胶管采集,甲醇溶剂解吸,苯甲醛衍生后衍生物为2-苯亚甲基氨基乙醇,氢火焰离子化检测器检测,以保留时间定性,峰面积定量建立了一套工作场所空气中乙醇胺的气相色谱分析方法。结果显示:乙醇胺在12.43~248.6μg/mL范围内线性关系良好,相关系数0.999 7,检出限0.23μg/mL,定量下限0.93μg/mL。按采样体积1.5 L计算,最低检出浓度0.15 mg/m^(3),最低定量浓度0.62 mg/m^(3),精密度1.0%~4.0%,解吸效率92.7%~101.0%,采样效率97.4%,常温下样品保存>7d。该分析方法各项指标均满足国家相关标准要求、高效便捷、对设备损伤小、推广性强。

一起特高压换流变压器油中总烃超标问题的分析和处理

某特高压换流变压器运行时油中总烃超标,最后被迫退出运行,返厂检修。利用油色谱分析、长时空载试验、局部放电试验、超声波定位、解体检查等手段,对故障原因进行分析,最终确定换流变压器总烃超标与三角形硅钢片、纠结线虚焊导致的两处过热点有关,并进行了相应处理,处理后换流变压器顺利通过了出厂试验,为类似故障的分析和处理提供了参考。

硅橡胶奶嘴中挥发性物质成分分析

目的溯源分析婴幼儿硅橡胶奶嘴的挥发性物质成分,评估健康风险。方法采用顶空气相色谱-质谱法挥发性物质非靶向筛查技术,分析挥发性物质总含量大于0.5%的硅橡胶奶嘴样品,通过100%迁移计算得到可能的最大迁移量。结果所测5种不合格硅橡胶奶嘴共检出16种挥发性有机物,包括环状/线性硅氧烷、醇类、醛类和芳香类物质。不同品牌奶嘴残留的挥发性物质种类区别较大。选择(+)-柠檬烯和正十三烷作为内标物进行半定量,依据标准限量和毒理学关注阈值法评估检出物的食品安全风险;多种硅氧烷的暴露量超过安全暴露阈值,需引起健康风险关注,特别是具有生物累积性的八甲基环四硅氧烷和十甲基环五硅氧烷。结论本研究开发的挥发性物质筛查和评估方法,适用于婴幼儿奶嘴的食品安全评价,样品检测结果表明,婴幼儿硅橡胶奶嘴中挥发性物质安全性需引起关注。

Separation of liquefied product of Salix psammophila by column chromatography and structure analysis of its components

The liquefied product of Salixpsammophila wood was separated by thin-layer chromatography （TLC） and column chromatography, and its structure was identified by nuclear magnetic resonance （NMR） spectra in our study. The separation result indicates that the sample of liquefied S. psammophila contained at least two categories of components. The structure of the main components was guaiacyl C-1, C-2 of the hydroxyphenyl propane, i.e., the aromatic nucleus protons of lignin. Degradation and polycondensation reactions occurred when the S. psammophila wood was liquefied in phenol. Polycondensation reactions occurred among the depolymerization products from cellulose, the aromatic depolymerization products from lignin and the products of the displacement reactions between phenoxide ion and cellulose.

Comparison of liquid-liquid extraction-thin layer chromatography with solid-phase extraction-high-performance thin layer chromatography in detection of urinary morphine

Liquid-liquid extraction-thin layer chromatography （LLE-TLC） has been a common and routine combined method for detection of drugs in biological materials. Solid-phase extraction （SPE） is gradually replacing the tra- ditional LLE method. High performance thin layer chromatography （HPTLC） has several advantages over TLC. The present work studied the higher efficiency of a new SPE-HPTLC method over that of a routine LLE-TLC method, in extraction and detection of urinary morphine. Fifty-eight urine samples, primarily identified as mor- phine-positive samples by a strip test, ＇were re-screened by LLE-TLC and SPE-HPTLC. The results of LLE-TLC and SPE-HPTLC were then compared with each other. The results showed that the SPE-HPTLC detected 74% of total samples as morphine-positive samples whereas the LLE-TLC detected 48% of the same samples. We further discussed the effect of codeine abuse on TLC analysis of urinary morphine. Regarding the importance of morphine detection in urine, the present combined SPE-HPTLC method is suggested as a replacement method for detection of urinary morphine by many reference laboratories.

Chromatographic fingerprinting and free-radical scavenging activity of ethanol extracts of Muntingia calabura L. leaves and stems

Objective: To determine the thin-layer chromatography(TLC) fingerprint profiles and to evaluate the in vitro antioxidant activity of ethanol extracts of Muntingia calabura(M. calabura) leaves and stems.Methods: The leaves and stems were extracted using ethanol as solvent. The TLC separation of the phytochemical constituents of the leaf and ethanol extracts was carried out in ethyl acetate: n-hexane and chloroform: ethyl acetate mobile phase systems.Distinct spots were visualized under visible light, UV 254 nm, UV 366 nm and after spraying with vanillin-sulfuric acid. The 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging assay was used to evaluate the antioxidant activity of the extracts.Results: Both the leaf and stem ethanol extracts at 4 mg/mL exhibited 2,2-diphenyl-1-picrylhydrazyl inhibition of more than 90%, relative to gallic acid. The results of TLC showed that the degree of resolution between the constituent spots was comparable between the two mobile phase systems using the different visualization wavelengths. Under the 254 nm visualization, few spots were observed in leaf and stem extracts. Visualization at 366 nm yielded the greatest number of observable spots of various colors in both leaf and stem extracts. More spots were visualized upon post-derivatization with vanillinsulfuric acid in the TLC chromatograms using chloroform: ethyl acetate mobile phase,compared to those in ethyl acetate: n-hexane mobile phase.Conclusions: M. calabura exhibited very high antioxidant activity in its leaves and stems ethanol extracts, both of which are used in traditional medicine. The TLC results demonstrated the presence of diverse secondary metabolites in the leaf and stem ethanol extracts, indicating that the antioxidant activity, including other bioactivities may be attributed to these phytochemical constituents. This paper has reported for the first time the TLC fingerprinting of M. calabura using visible light, UV 254 nm, UV 366 and postderivatization with vanillin-spray to visualize separate spots on TLC plates.

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.

气相色谱法测定高纯四氟化锗中的四氟化硅

高纯四氟化锗生产制备过程中,需要对四氟化锗中的气体杂质进行测定。针对高纯四氟化锗中混入的四氟化硅气体,建立了一套双柱并联—主组份反吹—气相色谱法测定高纯四氟化锗中四氟化硅的方法。通过1 mL定量环完成气体样品的定量进样,由一个十通阀和一个四通阀组成阀系统,采用气相色谱填充柱和HP-5ms超高惰性气相色谱柱分离四氟化锗中的四氟化硅,使用经过Valco HP2型氦气纯化器的氦气为载气和参比气,采用带TCD热导检测器的气相色谱仪,通过考察Valco HP2型氦气纯化器老化时间、柱箱温度、载气压力和切阀时间对四氟化硅标准气出峰情况的影响,确定了气相色谱法测定四氟化锗中四氟化硅的工作条件,Valco HP2型氦气纯化器老化时间为2 h,柱箱温度为恒温55℃,载气压力为0.6 MPa,参比气参比流量为30 mL/min,尾吹气5 mL/min,切阀时间为3.400 min。经过精密度实验、加标回收实验和实样测定实验验证,重现性良好,相对标准偏差RSD均小于1%,加标回收率在99.4%~100%,实样混合测定结果满足线性相加关系。方法精密度好、准确度高,四氟化锗中的四氟化硅能很好地分离,能够满足高纯四氟化锗生产中四氟化硅成分测定需求,可应用于实际测定工作中。

根区施用硅肥对‘玫瑰香’葡萄果实品质的影响

为调控果实采后的保鲜品质,在采前对9年生倾斜独龙干型展穗期的‘玫瑰香’树体在根区施用了不同剂量的硅肥,并在果实成熟期采用离子迁移谱(gas chromatography-ion mobility spectroscopy,GC-IMS)等方法测定了果实的挥发性组分及常规品质指标。结果表明,不同硅肥施用量(250、500、800 g·株^(-1))下‘玫瑰香’果实的几种常规品质指标(总糖、总酸、维生素C、可溶性固形物)含量分别为16.47%、17.97%、16.87%;0.325%、0.225%、0.300%;12.703、18.870、19.487 mg·100g^(-1);23.82%、22.59%、30.18%。硅肥施用量为800 g·株^(-1)时,总糖与总酸相较CK无显著变化(P>0.05),但维生素C和可溶性固形物大幅增加(P<0.05)。对果实挥发性物质分析发现,一些脂类物质的峰体积与硅肥施用量增加呈正相关,在800 g·株^(-1)时达到峰值,乙酸乙酯与丙酸乙酯的峰体积相较于CK变幅分别为70.89%、368.49%。表明增施硅肥达到一定剂量时对定向改变‘玫瑰香’果实品质有促进作用,为进一步探究这些物质对采后保鲜的影响奠定了理论依据。

Analysis of the Nucleoside Content of Cordyceps sinensis Using the Stepwise Gradient Elution Technique of Thin-Layer Chromatography

Nucleoside is the main class of active components in Cordyceps sinensis. Thin-layer chromatography (TLC) is one of the most commonly used methods in pharmacopoeias for analyzing chemical components of herbal medicine. Since the isocratic elution method cannot be applied successfully in TLC analysis for separating all the nucleoside components, the stepwise gradient elution has been developed in this work to separate eight nucleoside standards with success. In this way, quantitative analyses of the samples of Cordyceps sinensis were achieved via the pro-posed TLC procedure coupled with the scanning densitometric techniques of CAMAG and TLCQA methods for qualitative and quantitative analysis.

Preparation and Evaluation of Silicon Quantum Dots-Bonded Silica Stationary Phase for Reversed-Phase Chromatography

In this paper,silicon quantum dots(SiQDs)with green fluorescence are synthesized by solvothermal reaction of 3-(2,3-epoxypropoxy)propyltrimethoxysilane(GPTMS)and ethylenediaminetetraacetic acid(EDTA),and then SiQDs are bonded to the surface of silica to obtain a new nano-on-micro stationary phase(SiO_(2)-SiQDs)for reversed-phase chromatography.The successful preparation of SiO_(2)-SiQDs stationary phase is demonstrated by a variety of characterizations,such as transmission electron microscopy,laser confocal microscopy,elemental analysis and Fourier infrared spectroscopy.In addition,the chromatographic performance of the prepared stationary phase is evaluated and it shows good separation performance for non-polar substances such as alkylbenzene,aniline and polycyclic aromatic hydrocarbons in reversed-phase liquid chromatography.It is also verified that the stationary phase has good methyl selectivity and shape selectivity.More interestingly,the separation of prednisolone and hydrocortisone isomers can also be achieved at a low ratio of organic solvents,indicating that this new stationary phase has a good application prospect in isomer separation.

叶面喷施硅素对玫瑰香果实风味物质的影响

【目的】研究叶面喷施不同剂量硅素对玫瑰香果实风味物质及常规品质指标的定向调控效果,为玫瑰香葡萄生产中合理叶面喷布硅肥、品质定向调控提供科学依据。【方法】采用气相离子迁移谱技术(GC-IMS),检测分析玫瑰香果实风味物质等指标。【结果】在叶面喷施硅素处理的玫瑰香果实中检测出挥发性有机物47种,其中定性了32种,主要包括酯类、醛类、醇类和酮类。与CK相比,硅素浓度为200X时,乙酸丁酯的峰体积增大56.28%;硅素浓度400X时,苯甲酸甲酯的峰体积增大176.45%;600X时,乙酸丁酯的峰体积增大42.52%。对比发现,2-戊基呋喃、正己醇(二聚体)、正己醇、3-甲基-3-丁烯-1-醇、乙酸乙酯、丙酸乙酯(二聚体)、3-甲基丁醛等物质随叶喷硅素浓度升高,体积逐渐减小甚至消失。【结论】600X与CK相似,200X与400X相似。400X时,玫瑰香葡萄糖含量最高,为17.04%;总酸含量最少,为0.35%。

Simple and robust differentiation of Ganoderma species by high performance thin-layer chromatography coupled with single quadrupole mass spectrometry QDa

In this study,a high performance thin-layer chromatography/single quadrupole mass spectrometry QDa(HPTLC-QDa)method for robust authentication of Ganoderma lucidum,a popular and valuable herbal medicine,has been developed.This method is simple and practical,which allows direct generation of characteristic mass spectra from the HPTLC plates automatically with the application of in situ solvent desorption interface.The HPTLC silica gel plates were developed with toluene-ethyl formate-formic acid(5:5:0.2,V/V)and all bands were transferred to QDa system directly in situ using 80%methanol with 0.1%formic acid as desorption solvent.The acquired HPTLC-QDa spectra showed that luminous yellow band b3,containing ganoderic acid B/G/H and ganodeneric acid B,the major active components of Ganoderma,could be found only in G.lucidum and G.lucidum(Antler-shaped),but not in G.sinense and G.applanatum.Moreover,bands b13 and b14 with m/z 475/477 and m/z 475/491/495,respectively,could be detected in G.lucidum(Antler-shaped),but not in G.lucidum,thus allowing simple and robust authentication of G.lucidum with confused species.This method is proved to be simple,practical and reproducible,which can be extended to analyze other herbal medicines.