共查询到20条相似文献,搜索用时 250 毫秒
1.
以氧化锆微球为担体,通过mannich反应得到在氧化锆微球上键合8-羟基喹啉的痕量金属富集分离固定相,并对该固定相的键合金属离子能力进行了研究。以合成的氧化锆微球键合8-羟基喹啉金属鳌合固定相用作微柱流动注射(FIA)在线分离、富集和电感耦合等离子体质谱(ICP-MS)分析流程中的固定相,对大洋海水中的痕量铅和镉进行了在线分析,得到了较满意的结果。 相似文献
2.
一种亲水-亲油复合固相萃取填料的制备及其在食品安全检测中的应用 总被引:1,自引:0,他引:1
合成了一种以二乙烯苯和N-乙烯吡咯烷酮为单体的高分子聚合物固相萃取填料(DVB-NVP),以6种不同极性的化合物为模型化合物,结合高效液相色谱法(HPLC)对该填料进行了系统的评价,并与传统的C18填料及商品化同类型填料做对比;对填料进行了磺酸化修饰(DVB-NVP-SO3H),并将合成的填料应用于复杂基质中化合物的分析。结果表明:该填料对不同极性化合物的回收率在95.55%~101.08%之间,优于商品化C18填料,与商品化同类型填料相当。DVB-NVP对于白酒中邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丁酯的分析回收率分别为102.55%、102.99%、102.11%,相对标准偏差分别为2.11%、1.69%、0.79%; DVB-NVP-SO3H用于对猪肉中的可乐定和赛庚啶进行分析,回收率分别为89.23%和91.42%,相对标准偏差分别为8.21%和8.86%,符合生物样品分析要求。所合成的填料具有普适性,并具有较高的回收率,应用前景广泛。 相似文献
3.
建立了人体尿液中高香草酸含量的固相萃取-高效液相色谱-紫外测定方法.合成了弱阴离子超高交联树脂固相萃取填料,并对其进行吸附性能考察.利用此萃取剂对尿液中的高香草酸进行选择性吸附,洗脱液富集后以甲醇-乙酸(15∶85,V/V)溶液为流动相,C18为固定相,于280 nm测定其中的高香草酸.方法验证结果表明,高香草酸在2.26~145 mg/L浓度范围内呈良好的线性关系;检出限为0.45 mg/L;方法的平均加标回收率大于90%;RSD小于4.2%.采用本方法对8名健康人尿样中的高香草酸含量进行了测定,结果为1.55~6.79 mg/L.表明本方法选择性好、灵敏度高、准确可靠. 相似文献
4.
建立了同时测定饮料中5种食用合成色素的在线固相萃取-高效液相色谱-紫外检测(Online-SPE-HPLC-UV)方法。饮料样品用水稀释并经0.45μm微孔滤膜过滤后,在线固相萃取柱(Acclaim 120 C18)净化,反相C18分析柱分离,梯度洗脱,紫外检测器检测。结果表明:5种食用合成色素在0.5~20 mg/L浓度范围内线性关系良好,相关系数(r2)均大于0.999 9,检出限为0.02~0.08 mg/kg,3个水平下的加标回收率为94.5%~103.0%,相对标准偏差为0.4%~2.7%。该研究为快速准确地分离测定饮料中的食用合成色素提供了有效方法。 相似文献
5.
(2-甲基丙烯酰胺)乙氧基-2-甲基丙烯酸乙二醇单酯基质分子印迹手性分离介质的合成与表征 总被引:3,自引:1,他引:2
通过甲基丙烯酰氯和二甘醇胺反应设计合成了一种交联剂(2-甲基丙烯酰胺)乙氧基-2-甲基丙烯酸乙二醇单酯,以自行合成的(2-甲基丙烯酰胺)乙氧基-2-甲基丙烯酸乙二醇单酯为交联剂,丙烯酰胺为功能单体,合成了一种用于手性分离的N-叔丁氧羰酰-L-色氨酸(N-Boc-L-Trp,N-[(tert-butoxy)carbonyl]-tryptophan)的分子印迹聚合物。评价了该分子印迹聚合物作为高效液相色谱柱填料对N-叔丁氧羰酰-色氨酸(N-Boc-Trp)的手性拆分能力。结果表明:当检测波长为280 nm,流动相为V(甲醇)∶V(水)=80∶20,流速0.8 mL/min时,该填料实现了对N-Boc-Trp外消旋混合物的手性拆分,显示出良好的选择识别性能。 相似文献
6.
7.
通过在硅烷化硅胶内表面和外表面分别键合己胺和聚乙烯醇,制备了能够在线直接进样分析生物样品的新型内表面反相限进填料。采用元素分析、电镜观察对该限进填料的结构进行了表征。以普萘洛尔、阿替洛尔、苯巴比妥、卡马西平作溶质探针,并以Merck公司生产的限进填料柱作参比,对合成的限进填料的色谱性能进行了研究。研究结果表明,所制备的限进填料有较好的蛋白质排阻能力、富集能力和反相色谱性能,能同时实现排阻生物大分子杂质和富集小分子被分析物的功能,可作为在线、快速直接进样检测分析生物样品的预处理柱,适用于普萘洛尔血浆的直接进样分析。 相似文献
8.
采用甲基丙烯酸甲酯 (MMA)或MMA 亚乙基二甲基丙烯酸酯 (EDMA)在硅胶表面聚合的方法 ,制备生成了新型高分子覆盖型硅胶填料C或D。借助红外光谱、元素分析、尺寸排阻色谱和反相液相色谱分析对反应过程、覆盖程度、交联剂的影响和填料的色谱保留行为进行了评价和讨论。结果显示 ,在合成时可以通过控制聚合单体的量控制生成高分子层的厚度 ,而合成中加入交联剂可以改变填料表面的微孔构造。通过考察这种色谱填料的疏水性和对芳香族化合物的分离性能 ,认为其柱效和分离效果接近C18填料的性能。 相似文献
9.
采用固相萃取与双梯度高效液相色谱联用技术,建立了一种在线固相萃取-高效液相色谱同时测定动物源食品中维生素A、E的分析方法。样品于80℃下皂化反应30 min,经离心沉淀后引入一维C8固相萃取柱,采用60%(V/V)甲醇溶液对目标物进行在线富集净化,然后通过阀切换将其转移至二维液相分析系统进行分离检测。考察了萃取填料、上样溶剂及洗脱条件对猪肝、鸡蛋和配方乳粉的维生素A、E富集和基质净化效果。结果表明,在优化条件下,方法线性范围为0.02~20 mg/L,线性相关系数R2≥0.9998,对维生素A、E的检出限(S/N=3)为3.0~30.0μg/L,实际样品加标回收率为87.3%~115.0%,相对标准偏差(RSD)为1.8%~4.6%。本方法操作简便,灵敏度高,可用于动物源食品中维生素A、E的快速测定。 相似文献
10.
本文采用溶胶-凝胶方法合成SiO_2溶胶,制备了8-羟基喹啉改性的有序介孔SiO_2涂层毛细管,建立了毛细管微萃取-电感耦合等离子体质谱(CME-ICP-MS)在线联用技术分析铝形态的新方法.选择游离态铝和Al-柠檬酸络合物为不同铝形态的代表物,详细探讨了不同实验参数对铝形态分离的影响.结果表明:8-羟基喹啉改性的有序介孔SiO_2涂层毛细管在pH为5.0~8.0的范围内可以有效地分离试样中的稳定态单核铝(柠檬酸铝)和非稳定态无机单核铝(游离态铝).方法的富集倍数为10,检出限为0.34 ng·mL~(-1).该法应用于湖水、池塘水和长江水中铝的组形态分析,所得结果与8-羟基喹啉负载硅胶微柱分离所得结果吻合很好. 相似文献
11.
12.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted
indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator
model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was
established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing
analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997. 相似文献
13.
Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position. 相似文献
14.
The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations
were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples
were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of
hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the
best fitting experimental data.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
15.
Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6. 相似文献
16.
17.
18.
微量钙的测定方法研究进展 总被引:5,自引:0,他引:5
介绍了1995-2006年期间测定微量和痕量钙的方法,如电感耦合等离子体-原子发射光谱法、原子吸收光谱法以及离子色谱法等的工作原理和特点,并说明了其测定微量钙的应用领域。并对微量钙的测定技术进行了展望(引用文献55篇)。 相似文献
19.
Thermal behaviour of sodium oxo-salts of sulphur: Na2SO4, Na2S2O7, Na2S2O6, Na2SO3, Na2S2O5, Na2S2O4, Na2S2O3, Na2S3O6 and of sulphides Na2S and Na2S2 was studied on heating up to 1000°C. The experiments were performed with anhydrous compounds obtained from commercial products
by recrystallisation and dehydration. The stage mechanisms of decomposition of anionic sub-lattices of the salts have been
proposed basing on the Górski’s morphological classification of simple species. The thermal stability and the stage decomposition
mechanisms were correlated with the structure and the potential chemical properties of the salt anions. The thermal decomposition
processes were studied by means of thermal analysis, and the decomposition products were identified by means of X-ray phase
analysis. 相似文献
20.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared. 相似文献