气相色谱-质谱法同时测定饲料中6种雌激素类药物

建立了固相萃取/气相色谱-质谱法(GC-MS)同时测定饲料中己烷雌酚、己烯雌酚、双烯雌酚、雌酮、17β-雌二醇、雌三醇的检测方法。饲料样品经乙醚提取后,HLB固相萃取柱净化、衍生化后用气相色谱-质谱仪进行检测,外标法定量。结果表明,己烷雌酚在2.5~250 ng/m L,其它5种雌激素类药物在5~500ng/m L范围内具有良好的线性关系,相关系数不小于0.99,检出限为3~8μg/kg,样品的平均加标回收率为75.9%~96.3%。该方法检出限低,能够准确进行定性和定量测定,可同时测定饲料中的6种雌激素类药物。     

水产品中己烷雌酚、己烯雌酚与双烯雌酚残留的毛细管电泳测定

建立了毛细管电泳-紫外检测法测定水产品中己烷雌酚(HXS)、己烯雌酚(DES)及双烯雌酚(DIES)残留的新方法。研究了缓冲体系的酸度、浓度、添加剂、分离电压、进样时间及温度等对组分分离的影响。在检测波长为200 nm,分离电压为20 kV,运行缓冲液为50 mmol/L硼砂-25 mmol/L氢氧化纳(pH12.3,含30%的N,N-二甲基甲酰胺)的条件下,3种目标组分在14 min内达到基线分离。HXS、DES与DIES的质量浓度与峰面积分别在2.0~120、1.0~100、1.0~100 mg/L范围内呈良好线性,相关系数(r2)分别为0.9998、0.9992、0.9994,检出限为0.3~0.9 mg/L。将该方法用于鲫鱼中3种雌酚类激素的检测,结果令人满意。     

高效液相色谱分离牛奶中己烯雌酚、己烷雌酚和双烯雌酚

采用基质固相分散技术,对牛奶中己烯雌酚(DES)、己烷雌酚(HEX)和双烯雌酚(DS)残留进行提取和净化处理,并通过高效液相色谱进行分离。研究雌激素在C18,Florisil和N-丙基乙二胺(PSA)填料的保留行为,并研究不同流动相和色谱柱对3种雌激素的分离。实验结果表明,流动相为20 mmol/L磷酸/乙腈(42/58,V/V),流速1.0 mL/min,紫外波长230 nm。Xterra C18柱对3种雌激素分离最好。3种雌激素的平均回收率为84.1%~93.5%,相对标准偏差为3.5%~7.8%。DES、HEX和DS的检出限(LOD)分别为0.004,0.004和0.006 mg/kg,定量限(LOQ)分别为0.01、0.01和0.02 mg/kg;本方法可对样品进行灵敏、准确的定性定量分析。     

分子印迹固相萃取搅拌棒的制备及对复杂样品中双烯雌酚和己烷雌酚的萃取性能

以己烯雌酚为替代模板,利用整体材料的“原位”合成技术制备了分子印迹聚合物,并将其作为固相萃取搅拌棒的涂层(MIP-SBSE)制备了新的搅拌棒。详细考察了分子印迹聚合物制备条件中模板分子及功能单体用量对MIP-SBSE选择性萃取性能的影响,同时利用元素分析、扫描电镜和红外光谱对聚合物进行表征。以双烯雌酚(DS)和己烷雌酚(HS)为目标化合物,将MIP-SBSE与高效液相色谱-二极管阵列检测器联用,建立起复杂样品中DS和HS的分离分析方法。考察了吸附和解吸时间、解吸溶剂、离子强度和样品pH值等萃取条件对MIP-SBSE选择性萃取性能的影响。结果表明,在最佳萃取条件下,MIP-SBSE对DS和HS具有较高的选择性萃取性能,线性范围分别为1.0～400.0 μg/L和5.0～400.0 μg/L,利用氮吹再定容的方法,对DS和HS的检出限(S/N=3)分别可低至0.04和0.14 μg/L。在对实际污水、蜂蜜和牛尿样品的分析中取得了良好的加标回收率,其值为61.3%～120%。所建方法具有简便、高选择性和灵敏等特点,可用于复杂样品中双烯雌酚和己烷雌酚的分析监测。     

含己烷雌酚的聚磷酸酯的合成及其抗肿瘤活性研究

合成了３种主链含己烷雌酚的生物可降解的聚磷酸酯，结构经ＩＲ，＾１ＨＮＭＲ和元素分析鉴定，通过水接触角的测定研究了聚合物的亲水－疏水性能，以ｐＨ值变化表征了聚合物的体外水解速率。初步的体外实验表明，此类聚磷酸酯具有较好的体外抗艾氏腹水癌活性。     

动物组织中多种残留非类固醇同化激素的液相色谱-串联质谱法同时测定

用液相色谱-串联质谱(LC-MS/MS)同时测定动物组织中玉米赤霉醇(ZER)、玉米赤霉酮(ZEAR)、己烯雌酚(DES)、己烷雌酚(HEX)、双烯雌酚(DEN)。动物组织均质后,用叔丁基甲基醚和乙酸盐缓冲液加酶解剂分别提取试样中残留激素及代谢物,经硅胶柱净化,应用LC-MS/MS大气压化学电离负方式(APCI-),以多反应离子监测(MRM)方式进行检测,方法检测能力(CCβ)为0.143~0.496 ng.g-1。选用ZER、DES的同位素标记物作内标,内标法定量。DES、DEN在0.5~10 ng.g-1范围内回收率为58%~108%,ZER TAL、ZEAR、HEX在0.25~5 ng.g-1范围内回收率为66%~109%。     

环境水样中己烯雌酚与双烯雌酚的离子液体分散液-液微萃取/高效液相色谱法测定

以离子液体([Omim][PF6])为萃取剂,采用冷诱导分散液-液微萃取对环境水样中的己烯雌酚和双烯雌酚残留进行富集.优化后的萃取条件:在pH 3.0的条件下,以50 μL离子液体为萃取剂,0.8 mL甲醇为分散剂,采用反相 Extend-C18柱(5 μm, 250 mm×4.6 mm),流动相为水-甲醇(体积比40 ∶ 60),流速:1.0 mL/min,柱温:35 ℃,检测波长:245 nm.在优化的萃取条件下,己烯雌酚和双烯雌酚的线性范围均为2.5 ～200 μg/L,检出限(S/N=3)为80 ng/L.应用于环境水样中己烯雌酚和双烯雌酚的检测,加标回收率为93% ～98%,相对标准偏差为3.0% ～5.4%,建立的方法简单、环保.     

主链含己烷雌酚的聚酸酐的合成及其降解性能研究

聚酸酐是一类新型的药物控制释放载体材料,具有良好的生物相容性和表面溶蚀性能^[1].聚酸酐的降解和药物释放速率可通过改变单体结构、共聚物的组成和主链上的酸酐键密度实现.后者主要是把降解速率不同的酯键、酰(亚)胺键和磷酸酯键引入主链上.     

尼龙6纳米纤维膜的制备及其对己烷雌酚的吸附性能研究

采用静电纺丝设备制备尼龙6纳米纤维膜。用静、动态吸附方法,研究了尼龙6纳米纤维膜对己烷雌酚的吸附性能,考察了吸附时间、初始浓度及介质p H值对尼龙6纳米纤维膜吸附己烷雌酚的影响。结果表明,初始浓度为2mg/L时,尼龙6纳米纤维膜吸附己烷雌酚的过程符合准一级动力学模型;当初始浓度在5~20mg/L范围内,吸附过程符合准二级动力学模型。尼龙6纳米纤维膜吸附己烷雌酚的过程符合Freundlich等温吸附模型。     

2-羟基脱氧雌酚酮的合成

2-羟基雌甾化合物是人体内对生理机能有重要意义的雌激素代谢产物,其在生物体内的含量极少,需用化学方法合成来满足研究、应用的需要。迄今为止,已报道了较多合成2-羟基和4-羟基雌甾化合物的方法[1-3],但选择性和产率并不十分理想。我们在文献报道的合成路线[1]的基础上,合成了     

Liquid chromatographic determination of nicarbazin in feeds

A new liquid chromatographic method has been developed for determination of nicarbazin in feeds. Approximately 40 g feed is extracted with 200 mL acetonitrile-water (80 + 20, v/v). An aliquot of the extract is filtered and assayed using a reversed-phase isocratic method that measures the 4,4'-dinitrocarbanilide moiety of nicarbazin at a wavelength of 340 nm. For medicated feeds, the method uses a standard linear range of 5 to 100 microg/mL. For lower levels, a linear range of 50 to 150 ng/mL can be used. The method has a limit of detection of 250 ng/g and a limit of quantitation of 500 ng/g in a 40 g feed sample. Recovery was 99.1%, with a range of 95.2 to 101.8%. In the typical U.S. dosing range of 27 to 113.5 g/ton, the precision of the method based on one analyst, one day, and 2 weighings ranged from 2.8% (113.5 g/ton) to 4.7% (27 g/ton).     

Reversed-phase liquid chromatographic determination of riboflavin in feeds

A method for determination of riboflavin in animal feeds using liquid chromatography (LC) was developed for feed samples fortified with riboflavin at 1 mg/lb or greater (up to 10,000 mg/lb). Feed samples were extracted in 0.1 N HCl with heating on a steam bath for 30 min, followed immediately by mechanical shaking for 30 min. Sample extracts were diluted to target volume with 2% acetic acid and filtered; riboflavin was determined by LC on a reversed-phase C18 column with 2% acetic acid-acetonitrile (85 + 15) mobile phase for separation and fluorescence detection with excitation at 460 nm and emission at 530 nm. The extraction was compared with that of the AOAC Official Method for riboflavin in food and feed premixes. The 2 method extractions were not significantly different from each other at the 95% confidence level. The developed method also had good linearity over 4 orders of magnitude, recovery of 95-99% from spiked feed samples, a limit of detection of riboflavin at 0.00034 microg/mL in solution, a limit of quantitation of 0.023 mg/lb in feed, and good ruggedness.     

Quantitative determination of moniliformin in vegetable foods and feeds

Summary A suitable and simple method for the quantitative determination of moniliformin in vegetable foods and feeds is described. The mycotoxin was extracted by Soxhlet extraction with methanol from mouldy maize, rice, rye, oats, wheat and barley samples. Moniliformin was determined by thin-layer chromatography (TLC) using N-methylbenzthiazolon-2-hydrazone (MBTH) as a new derivatization reagent for this mycotoxin. The moniliformin derivative was assayed at 518 nm. Quantification could be performed after calibration. A linear relationship between mycotoxin amount and peak area was found from 100 to 400 ng/spot. The detection limit is 75 ng/spot.

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Quantitative Bestimmung von Moniliformin in pflanzlichen Nahrungs- und Futtermitteln

Zusammenfassung Eine geeignete Analysenmethode zur Bestimmung von Moniliformin in Nahrungs- und Futtermitteln wird beschrieben. Das Toxin wurde aus verschimmeltem Mais, Reis, Roggen, Hafer, Weizen und Gerste extrahiert. Der Extrakt wurde anschließend dünnschicht-chromatographisch getrennt und Moniliformin mit N-Methylbenzthiazolon-2-hydrazon (MBTH), einem für den DC-Nachweis neuen Reagens, nachgewiesen. Das gebildete Moniliforminderivat konnte bei 518 nm in Remission bestimmt werden. Mit Hilfe einer Eichkurve wurden die erhaltenen Daten quantitativ ausgewertet. Ein linearer Zusammenhang zwischen Substanzmenge und Peakfläche besteht für den Bereich von 100–400 ng pro Fleck. Die Nachweisgrenze beträgt nach dieser Methode 75 ng/Fleck.

     

烟用香精中风味成分的提取条件的优化与测定

分别采用溶剂萃取、同时蒸馏萃取、固相微萃取和水蒸汽蒸馏等4种方法提取烟用香精B3样品中的挥发性和半挥发性风味成分,并采用信息量和重现性两个指标考察最优提取方案。正己烷溶剂萃取法具有相对较高的信息量和理想的重现性。通过GC和GC-MS进行定性定量分析,共鉴定了34种成分,定性了的成分占总成分的85．4％。     

The determination of impurities in caprolactam by capillary gas chromatography-mass spectrometry

A capillary gas chromatography-mass spectrometry (GC-MS) technique has been developed for the determination of impurities in caprolactam. The residual solution of the crude product extracted by benzene was analyzed. A total of 28 compounds in the residual solution were separated. In comparison with the mass spectra obtained with those published in data tables, 24 compounds of the 28 were identified. The possible origination of these impurities was discussed and could be significant in the industrial control of caprolactam.     

Peak height determination in analysis of chlortetracycline in animal feeds

Summary In an HPLC method for the analysis of chlortetracacline (CTC) in animal feed, a problem arose with the presence of peaks which did not return to baseline before the occurrence of a subsequent peak. Two methods were used to determine the peak height. In the first method, a perpendicular was dropped from the maximum of the second peak. A linear function was then fitted to the descending slope on the first peak. The point of intersection was taken as the baseline point. In the second approach, a polynomial fit was used instead. Results show excellent agreement with analysis obtained by established methodology. This approach provides a practical method for determination of chlortetracycline in animal feeds allowing up to six samples to be analyzed within 8 hours.     

Simultaneous determination of 16 sulfonamides in animal feeds by UHPLC-MS-MS

A fast and sensitive method was developed for the simutaneous quantitative determination of 16 sulfonamides in animal feeds using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS-MS). With the developed method, a feed sample can be analyzed in less than 2 h. A solid phase extraction method using acetonitrile and basic alumina column was developed to extract and purify sulfonamides from animal feeds. The analysis time can be greatly reduced with this method compared with previous reports. A linear range of 0.2 approximately 40 ng/mL (R(2) > 0.996) were obtianed for most of the compounds. The limits of quantification for all sulfonamides were in the range of 0.5 approximately 20 μg/kg. The high precision and accuracy of this method were represented by average recoveries ranging from 80% to 120% and coefficients of variation of less than 10% for spiked animal feed samples. The method is suitable for fast determination of sulfonamides in concentrates, premixes, and complete feeds.