高效液相色谱法同时测定禽肉中土霉素、四环素、金霉素、强力霉素残留的研究

建立了一种高效液卡甘色谱法同时测定禽肉中土霉素、四环素、金霉素、强力霉素残留的分析方法、禽肉样品用0．1mol／L Nac EDTA—Mollvaine缓冲溶液提取,清液用Oasis HLB固卡甘萃取柱和Carboxylic acid阴离子交换柱净化,用流动卡甘洗脱定容后,用紫外检测器于350nm,测定一在5～100μg／kg添加水平、回收率为60％～100％,相对标准偏差在16％以内土霉素、四环素的检出限为2μg／kg,金霉素、强力霉素的检出限为5μg／kg。     

反相高效液相色谱法快速测定7种四环素类抗生素

建立了一种反相高效液相色谱梯度洗脱分离测定四环素类药物的新方法。采用DiamonsilTM C1 8ODS(2 5 0mm× 4 .6mmi.d ,5 μm)色谱柱 ,以甲醇 乙腈 0 .0 1mol/L草酸为流动相 ,流速 1.0mL/min ,2 70nm检测 ,在10min内分离检测四环素等 7种化合物。同时还研究了流动相组成、梯度条件、pH值、草酸浓度等因素对分离效果的影响。     

固相萃取–超高效液相色谱法测定土壤中土霉素、四环素及金霉素

建立土壤中土霉素、四环素、金霉素残留量检测的固相萃取-超高效液相色谱法.向样品中加入Na2EDTA–Mcllvaine–甲醇提取液,振荡离心后,上清液过HLB固相萃取柱净化富集.采用Agilent C18色谱柱(250 mm×4.6 mm,4.6μm),以甲醇–乙腈–0.01 mol/L草酸溶液(体积比为8:8:84)...     

高效液相色谱法测定肉类食品中四环素类抗生素残留

肉类食品中抗生素的残留来源于饲养添加有抗生素的饲料，它可以防病，对幼畜禽的发育有促进作用和治疗过程中使用抗生素。饲料中添加的各类抗生素达23种之多，其中四环素类占57％。抗生素对人体有一定的危害，使机体内病菌耐药性增加，造成人体免疫系统的功能降低。目前测定抗生素的方法有微生物法、高效液相色谱法。本文应用岛津LC-4A高效液相色谱仪测定肉类抗生素残留量，对色谱分离实验参数，包括色谱柱、流动相配比、缓冲液、pH、温度、检测波长等，进行了系统的试验，使肉类食品中的四环素、土霉素和金霉素能够同时分离和定量测定。     

高效液相色谱法测定化妆品中九种禁用四环素类抗生素的方法研究

建立了用反相高效液相色谱法同时测定化妆品中9种禁用四环素类抗生素. 采用甲醇超声提取, Kromasil C18柱(250 mm×4.6 mm i.d., 5 μm)分离测定. 9种被测物在12 min内均得到良好的分离. 在1～100 μg/mL范围内均与其各自对应的峰面积呈良好线性关系(r≥0.9991), 回收率在85.5%～105.7%之间, 精密度RSD＜3.2%, 该方法的检出限(S/N=3)为0.05～0.5 μg/mL. 该法可用于祛痘类化妆品中9种禁用四环素类抗生素的检测.     

高效液相色谱法快速测定蜂蜜中四环素族抗生素

建立了一种快速、准确、完善的测定蜂蜜中四环素族抗生素的反相高效液相色谱方法。研究了流动相配比、pH值、流速等因素对分离效果的影响，并且选出了它们的最佳值。试验和优化了两种蜂蜜样品的前处里方法，得到了满意的效果。灵敏度为4．8×10-8mol／L，回收率为96．18％。     

固相萃取-高效液相色谱法测定乳及乳制品中土霉素、四环素和金霉素残留

建立了固相萃取-高效液相色谱同时测定乳及乳制品中土霉素、四环素和金霉素的方法。样品经pH 4.0的Na2EDTA-mcllvaine缓冲溶液漩涡超声提取后,采用Oasis HLB固相萃取(SPE)小柱净化,洗脱液用N2吹至近干后用流动相溶解并定容,过PTFE滤膜后在Shiseido MG C18色谱柱上,以V(乙腈):V(10 mmol/L草酸)=27∶73的溶液为流动相进行分离,检测波长为360 nm。在最优的色谱条件下,各目标化合物的加标回收率为83.0%~109.2%,相对标准偏差在2.8%~6.1%之间。3种抗生素含量在0.10~20.0 mg/L范围内线性关系良好,相关系数≥0.999,乳及乳制品中土霉素、四环素和金霉素的检出限分别为10,10和20μg/kg。     

高效液相色谱法分离测定人参中的6种人参皂甙

 采用梯度法,以乙腈-水溶液为流动相,用高效液相色谱法分离人参中的6种主要人参皂甙,并采用紫外检测器检测,在203 nm处测定4种人参样品。该方法在25 mg/L～300 mg/L的范围内有良好的线性关系,回收率高于80%。     

高效液相色谱法测定头孢他啶的含量及杂质

采用高效液相色谱法测定了头孢他啶的含量及杂质。以Alltima C18色谱柱(250 mm×4.6 mm,5 μm)为分离柱,以乙腈和磷酸盐缓冲溶液(pH 3.9)分别为流动相A和流动相B进行梯度洗脱,流速1.3 mL/min,柱温35 ℃,紫外检测波长255 nm。从头孢他啶药物中共分出14个杂质,且14个杂质间具有良好的分离度。头孢他啶在0.267~1069 μg/mL范围内与峰面积具有良好的线性关系(r=1.0000);其定量限(S/N=10)和最低检出限(S/N=3)分别为3.1 ng和0.93 ng。3个浓度的日内测定值的相对标准偏差(RSD）为0.72%(n=3),日间测定值的RSD为0.91%(n=3)。头孢他啶溶液在4 ℃避光条件下放置24 h保持稳定。本方法与欧洲/英国药典和日本药局方的方法比较,具有分离杂质数量多、分离度好的优点。     

饲料中四环素类药物含量的高效液相色谱测定

建立了高效液相色谱法测定饲料中四环素类药物含量的方法。样品经甲醇-盐酸溶液提取,WatersOasis HLB固相萃取柱净化,进行HPLC分析。标准校正曲线线性范围为0.05~2.0 mg/L,相关系数r>0.999。饲料中土霉素、四环素、金霉素和强力霉素的定量下限(LOQ)依次是2.0、2.0、4.0和4.0 mg/kg;不同添加水平样品加标回收率为78%~103%,RSD小于11%。     

Simultaneous Determination of Oxytetra- cycline, Doxycycline, Tetracycline and Chlortetracycline in Tetracycline Antibiotics by High-Performance Liquid Chromatog- raphy with Fluorescence Detection

A simple, rapid and sensitive high-performance liquid chromatographic method with fluorescence detection for the simultaneous determination of oxytetracycline, doxycycline, tetracycline and chlortetracycline was developed, and successfully applied to the analysis of commercial tetracycline antibiotics. The separation was performed on a reverse-phase C₁₈ column with a gradient elution composed of methanol and sodium acetate buffer (containing disodium ethylenediaminetetraacetate and calcium chloride, pH 8.10) as the mobile phase, and fluorescence detection at 532 nm (excitation at 380 nm). The detection limits for oxytetracycline, doxycycline, tetracycline and chlortetracycline were 0.1, 0.5, 0.3 and 0.4 g L^–1, respectively. Data with respect to precision and accuracy were reported and discussed.     

Analysis of Tetracycline,Oxytetracycline and Chlortetracycline in Plasma Extracts by Electrospray Tandem Mass-Spectrometry and by Liquid Chromatography

Abstract

Pure standards of tetracyclines (tetracycline, oxytetracycline and chlortetracycline) have been analyzed on a triple quadrupole mass spectrometer with Atmospheric Pressure Chemical Ionization (APCI) and Electrospray Ionization (ESI). ESI appeared to be considerably more sensitive than APCI. Collisional activation of the MH⁺ ions gave fragment ions at m/z values equal to MH⁺ - 35 which corresponds to loss of both H₂O and NH₃. The collisionally induced loss of 35 from MH⁺ was used in developing a mass spectrometric method based on loop injection and selected reaction monitoring (SRM) as the final analytical step. The method was tested on extracts from fortified plasma and the measurements from the MS-MS analysis were compared with results from High Performance Liquid Chromatography (HPLC) analysis of the same samples. The fortified plasma (from pig) samples were purified by chelate affinity chromatography (amberlite XAD columns). After filtration and evaporation of the solvent the redissolved residues were analyzed by HPLC and by MS-MS with ESI. The HPLC eluates (gradient of 0.01 M aqueous oxalic acid and CH₃CN) were monitored at 356 and 369 nm. The signal to noise ratio in the analyses of extracts from plasma fortified to 20 ppb suggests a detection limit for the MS-MS method below 10 ppb of tetracylines in plasma.     

Separation of Tetracycline Antibiotics by Hydrophilic Interaction Chromatography Using an Amino-Propyl Stationary Phase

In this work the potential of hydrophilic interaction chromatography (HILIC) is explored for the analysis of tetracycline antibiotics. The choice of the polar stationary phase is first discussed and it is demonstrated that aminopropyl stationary phases lead to higher efficiencies and peak symmetry than bare silica ones. The influence of the composition of the mobile phase is studied next : the concentration of the weaker solvent (acetonitrile), the nature and concentration of the more polar solvent (water or methanol), pH, the nature and ionic strength of the buffer. It is shown that high efficiencies are reached only with a citrate buffer that impairs the interactions with the residual silanol groups whatever the mobile phase pH is. We demonstrate that the citrate buffer strongly interacts with the cationic moiety of the aminopropyl stationary phase and thus reduces the accessibility of silanols. The separation of oxytetracycline, tetracycline and chlortetracycline is achieved in a few minutes at pH 3.5 or 5, with no peak tailing as usually observed in reversed phase liquid chromatography with an opposite elution order when compared with reversed phase liquid chromatography.     

Determination of flavonoids,phenolic acid and polyalcohol in Butea monosperma and Hedychium coronarium by semi-preparative HPLC Photo Diode Array (PDA) Detector

The semi preparative HPLC method with PDA Detector was proposed for the determination of one phenolic acid, three flavonoids and one polyalcohol from Butea monosperma and Hedychium coronarium in gradient elution system. The influence of composition of the mobile phase concentration of the mix modifier and temperature on the separation of gallic acid, quercetin, iso-butrin, butrin and eugenol for 90 min was studied. Two different gradient programmes were used to separate these components. The lower limit of quantification of phenolic acid, flavonoids and eugenol is 0.050–0.150 μg/mL and was determined by the least square method and a good correlation was obtained for all separated components.     

New Colorimetric Method for Determination of Tetracycline and Oxytetracycline Via Charge Transfer Complex Formation

Abstract

A colorimetric method for the determination of tetracycline and oxytetracycline is developed. It depends on nitration and reaction of the nitroderivatives with acetone in the presence of potassium hydroxide. A highly colored complex is produced. Variables such as temperature) time of heating, volume of nitrating mixture, acetone and potassium hydroxide have been evaluated to permit the selection of the most advantageous technique. Beer's Law is obeyed over the concentration range from 0.004 – 0.04 mg ml for tetracycline and oxytetracycline.     

四环素类抗菌素碱性降解物与碱土金属螯合物的荧光研究

临床医学发现,给病人服用四环素后定时测定体液中四环素含量,可以诊断胃癌~[1],因此.建立灵敏、准确的四环素测定方法具有重要意义.已知四环素类抗菌素与一些金属离子有很强的螯合能力,并能生成有色螯合物,其中以锆、钍、铀、锌、铜、铝、镁、铈及钴的螯合物尤为稳定,可用于鉴别、测定四环素类抗菌素的含量.一些螯合物也用于荧光测定~[2～6],但     

环境样品中四环素类抗生素的检测技术*

抗生素的大量生产及滥用所造成的环境污染近年来引起国内外极大关注,其中环境样品中痕量抗生素的检测一直是分析工作者致力解决的问题 ,而国内的相关报道较少。四环素类抗生素是临床上重要的一类抗感染药物,在畜牧业及水产养殖业中广泛应用,对环境造成潜在威胁。本文总结了四环素类抗生素的基本性质,介绍了被该类抗生素污染环境样品（如土壤、水样）的采集和储存及样品前处理技术,综述了环境样品中该类抗生素检测技术的研究进展,并探讨了这一领域存在的问题及可能的发展方向。     

液相色谱梯度淋洗过程中溶剂的分布规律

在液相色谱梯度淋洗过程中,由于柱外过程和流动相在柱内的输运过程中的延迟作用和扩散的影响,使得溶剂浓度梯度变化时,在柱内特定位置的浓度随时间的变化符合相应的分布规律.本文从理论和实验两个方面对这一规律加以探讨,并讨论了仪器条件对该分布规律的影响.