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1.
本文报道树脂法从混合物中分离纯化邻硝基苯甲醛的方法。研究说明,通过伯胺树脂与醛的反应对邻硝基苯甲醛进行化学吸附,可以将邻硝基苯甲醛从含有邻硝基甲苯、邻硝基苯甲醛、邻硝基溴苄、邻硝基-α,α─二溴苄、以及邻硝基苄醇的混合物中有效地分离出来。  相似文献   

2.
采用微波消解溶样,结合离子交换法对色母粒样品进行待测元素的提取及净化处理,利用原子荧光光度计进行镉含量的测定。研究了717型阴离子交换树脂对色母粒样品中镉的吸附及分离条件,解决了样品中铅、铜等元素的干扰问题。方法加标回收率在92.4%~117.4%之间,相对标准偏差小于3.0%。  相似文献   

3.
A green and efficient method for large‐scale preparation of glycyrrhizic acid from licorice roots was developed by combination of polyamide and macroporous resin. The entire preparation procedure consisted of two simple separation steps. The first step is to use polyamide resin to remove licorice flavoniods from the licorice crude extract. Subsequently, various macroporous resins were tried to purify glycyrrhizic acid, and HPD‐400 showed the most suitable adsorption and desorption properties. Under the optimized conditions, a large‐scale preparation of glycyrrhizic acid from licorice roots was carried out. A 20 kg raw material produced 0.43 kg of glycyrrhizic acid using green aqueous ethanol as the solvent. The purity of glycyrrhizic acid was increased from 11.40 to 88.95% with a recovery of 76.53%. The proposed method may be also extended to produce large‐scale other triterpenoid saponins from herbal materials.  相似文献   

4.
A new method for determination of Cu(Ⅱ) by DDCT chelating resin preconcentration and thin layer resin phase spectrophotometry was developed. The method has a high sensitivity (ε435 =3.6×105 L/mol· cm), which is 33 times higher than that of liquid phase spectrophotometry. It has a good selectivity (most coexisting ions could not influence determination) and an ideal precision [30μg Cu(Ⅱ), n=6, RSD= 1.67%]. The content of Cu(Ⅱ) in water, high purity rare earth and its oxide was determined. The detection limit of Cu(Ⅱ) is 5.3μg/L, and the linear range is 0~7.2 μg/ml. The result is satisfactory.  相似文献   

5.
A new method has been developed using (bis-3,4-dihydroxy benzyl)p-phenylene diamine functionalized to XAD-16 (a polystyrene divinyl benzene copolymer) matrix, to preconcentrate mainly U(VI) and Th(IV) from synthetic and real samples. The developed method is free from matrix interference due to alkali and alkaline metal ions and preconcentrates the actinides with a high degree of selectivity, with consistent trace recoveries. The new chelating resin provides dramatic improvement in metal exchange rate, with half value saturation time (t1/2) of less than 1.6 min. The developed method was superior in its metal loading capacity for U(VI) and Th(IV), with values of 0.666 and 0.664 mmol g−1, respectively. Various physio-chemical properties like effect of solution pH, kinetic studies, resin loading capacity, sample breakthrough volume, matrix effects etc., on metal ion sorption to sorbent phase, were studied using both batch and column method. The new chelatogen was applied to extract U(VI) from near neutral real water samples. Preconcentration and separation of metal ions were possible through pH variation and also by varying the eluant concentration. A high preconcentration factor value of 350 with a lower limit of detection of 20 and 30 ng cm−3 was obtained for U(VI) and Th(IV), respectively. The practical applicability of the developed resin was examined using synthetic and real samples such as sea/well water samples. The method provides low relative standard deviation values of <3.5% for all analytical measurements, reflecting on the reproducibility and accuracy of the developed method. The new resin is quite durable with recycling time >35 cycles, without any major change in its quantitative metal uptake nature.  相似文献   

6.
本文合成了Amberlite XAD-4键合4-(2-吡啶偶氮)-间苯二酚螯合树脂,并考察了其对痕量镉(Ⅱ)的吸附性能。探讨了溶液pH、洗脱剂和干扰离子等对镉(Ⅱ)分离富集的影响。树脂吸附容量为4.7mg/g,吸附的镉(Ⅱ)用5mL 2mol/L HNO3乙醇溶液洗脱,火焰原子吸收法测定。在最佳实验条件下,回收率为94.4%~97.9%,相对标准偏差在1.7%~2.7%之间。方法可用于蔬菜中镉(Ⅱ)的测定。  相似文献   

7.
以抑菌圈为指标,通过离子交换法对双效菌素Zwittermicin A进行了分离纯化,并研究其抑菌活性。首先通过静态法比较D151、D113、D001-cc 3种大孔阳离子交换树脂吸附效果,结果表明,D151对ZwittermicinA分离纯化效果最好。利用单因素轮换法,确定了ZwittermicinA的最佳纯化工艺为:上柱样品的最佳pH=7;第1次冲洗液NH4H2PO4的最适浓度为5mmol/L;第2次冲洗液CH3COONH4的最适浓度为30mmol/L;1mol/L氨水洗脱液的最少用量为12.7mL/cm3树脂;Zwittermicin A的总收率达90%以上。利用红外光谱仪对D151树脂的吸附前后进行了分析。  相似文献   

8.
A new method for the determination of Fe by thin layer resin phase spectrophotometry in alkali condition was reported. The complex anion formed by Fe(Ⅱ) and VA was absorbed on the 717#resin and Fe was determined by making thin layer. This method had a high sensitivity (ε620=3.0×105 L/mol·cm), which was 15 times higher than that of liquid phase spectrophotometry. It had been proved a satisfactory precision (5.0μg Fe, n=6, RSD=1.8%). The trace Fe in natural water was determined and the recovery was 97%.  相似文献   

9.
制备了一种紫外光固化预聚物——带有羧基的低分子量聚丙烯酸酯丙烯酸树脂(Polyacrylate acrylic resin, PAAR).其主链由丙烯酸烷基酯和丙烯酸进行共聚而得,当采用丙烯酸甲酯、丙烯酸乙酯和丙烯酸(摩尔比1:1:1)作为共聚单体,引发剂AIBN为1.5%,链转移剂十二硫醇为2.5%时,聚合得到的聚丙烯酸酯(Polyacrylate, PA)分子量在1100-1400之间,多分散性小于2,反应速率快,转化率高;由这种PA和甲基丙烯酸缩水甘油酯(GMA)进行酯化反应,制备得到最终产物聚丙烯酸酯丙烯酸树脂,酯化率可以达到80%以上,其光固化膜具有较好的涂膜硬度和柔韧性,光泽度饱满.  相似文献   

10.
Salvianic acid A (also known as danshensu) is a plant‐derived polyphenolic acid, and has a variety of physiological and pharmacological activities. Our laboratory previously constructed an unprecedented artificial biosynthetic pathway in Escherichia coli and established the fermentation process to produce salvianic acid A. Here, we developed an efficient method for separating salvianic acid A from the fermentation broth of engineered Escherichia coli by macroporous resins. Among ten tested macroporous resins, the static and dynamic adsorption/desorption experiments demonstrated that X5 resin was the best to separate salvianic acid A from fermentation broth. Other parameters during static and dynamic procedures were also investigated. Under the optimum separation conditions, the average adsorption capacity of SAA were 10.66±0.54 mg/g dry resin and the desorption ratio was 85.6±4.1%. The purity and recovery yield of salvianic acid A in the final dry product were 90.2±1.5 and 81.5±2.3%, respectively. The results show that adsorption separation with macroporous resin X5 was an efficient method to prepare salvianic acid A from fermentation broth. This work will benefit the development and application of plant‐derived salvianic acid A and its derivatives.  相似文献   

11.
A novel method to separate and purify tea seed polysaccharide and tea seed saponin from camellia cake extract by macroporous resin was developed. Among four kinds of resins (AB‐8, NKA‐9, XDA‐6, and D4020) tested, AB‐8 macroporous resin possessed optimal separating capacity for the two substances and thus was selected for the separation, in which deionized water was used to elute tea seed polysaccharide, 0.25% NaOH solution to remove the undesired pigments, and 90% ethanol to elute tea seed saponin. Further dynamic adsorption/desorption experiments on AB‐8 resin‐based column chromatography were conducted to obtain the optimal parameters. Under optimal dynamic adsorption and desorption conditions, 18.7 and 11.8% yield of tea seed polysaccharide and tea seed saponin were obtained with purities of 89.2 and 96.0%, respectively. The developed method provides a potential approach for the large‐scale production of tea seed polysaccharide and tea seed saponin from camellia cake.  相似文献   

12.
铝盐是工业生产及城市给水处理中广泛使用的无机盐,随废水排入江河中,造成水体污染。已经证实铝与老年痴呆症和甲状腺亢进等疾病有关,过多摄入还会导致人体免疫力下降,小儿智力低下及行为异常[1]。因此,我国在新制订的《城市供水行业2000年技术进步发展规划》中,将铝列为常规监  相似文献   

13.
研究了717型阴离子交换树脂柱分离-富集钼的条件,建立了分光光度法测定尾矿中微量钼的方法。在pH 7.5的条件下,钼以MoO42-形式被树脂定量吸附后,采用体积比1:1的2 mol/L HNO3和0.5 mol/L NH4NO3混合溶液洗脱,消除了绝大部分共存离子的干扰。结果表明,采用硫氰酸盐光度法,体系的最大吸收波长为460 nm,线性范围为0~120.0μg/L,检出限为1.3μg/L。对实际样品测定结果与ICP-AES法相符,6次测定值的RSD=3.3%,加标回收率在96.2%~105.7%之间。  相似文献   

14.
A rapid and simple on-line method is described for the determination of Au(III) in various samples. The method is based on the sorption of gold(III) on Lewatit MonoPlus TP207 chelating resin including the iminodiacetate group, which is used as sorbent material and packed in a minicolumn. The chemical variables such as the pH of the sample solution, eluent type, interfering ions and concentrations of reagents, and instrumental variables such as sample loading volume, reagents flow rates, and tubing length, which affect the efficiency of the method were studied and optimised. Au(III) was sorbed on the chelating resin, from which it could be eluted with 3 mol L?1 HCl, and then introduced directly to the nebuliser-burner system of FAAS. The limit of detection of the method was 0.2 µg L?1 while the relative standard deviation was <4.0% for 20 µg L?1 Au(III) concentration. The preconcentration factor was found to be 106 while the optimised sample volume was 15.3 mL. The accuracy of the method was verified by analysing the certified reference material. The developed method was applied successfully for the determination of gold in different samples with satisfactory results.  相似文献   

15.
合成了一种含三嗪环结构的环氧树脂固化剂2,4,6-三(羟基苯甲基氨基)-均三嗪(MFP).用动态DSC和原位红外光谱对MFP/DGEBA(双酚A型环氧树脂)体系的固化行为进行了研究.动态DSC研究表明,由于MFP分子结构中存在两种活泼氢(酚羟基氢和仲胺氢),固化反应存在明显的两个峰,相对应的表观活化能分别为70.5 kJ.mol-1和86.5 kJ.mol-1(Kissinger法),通过与另一相似化合物固化DGEBA的比较可知,在MFP固化DGEBA的过程中,酚羟基与环氧基反应相对较难.原位红外动力学结果很好地支持了上述结论.  相似文献   

16.
该文建立了大孔树脂-高速逆流色谱分离薇甘菊中黄酮类物质的方法。分离条件为:采用大孔树脂AB-8,洗脱液为50%(v/v)乙醇水溶液,高速逆流色谱溶剂体系为正丁醇-乙酸-水(4:1:5,v/v)。从薇甘菊中分离到4种黄酮类物质:槲皮素-3-O-芸香糖苷(纯度90.2%)、山奈酚-3-O-芸香糖苷(纯度98.55%)、木犀草苷(纯度98.33%)和紫云英苷(纯度99.23%)。建立的大孔树脂-高速逆流色谱方法简单、高效,可扩展应用于从其他植物中分离黄酮类物质。  相似文献   

17.
《Analytical letters》2012,45(5):745-756
A new method was developed using weak anion exchange resin modified with sodium diethyldithiocarbamate (DDTC) for the derivatization and preconcentration of copper(II) in water prior to spectrophotometric determination. Several conditions affecting the extraction efficiency were investigated. Under the optimum conditions, an enrichment factor of 50 was achieved. The reaction mechanism of copper(II) and DDTC on the resin and binding experiment was studied. The detection limit is 0.6 μ g L?1. The relative standard deviations of intra- and inter-day ranging from 2.1 to 3.6% and from 1.3 to 4.0% were obtained, respectively, and the recoveries were in the range of 95.3–99.6%.  相似文献   

18.
A sensitive and simple method of ion-exchange resin separation and graphite-furnace atomic absorption spectrometry (GFAAS) detection was proposed for the determination of inorganic vanadium species. Methylene Blue (MB) was used as a chelating agent of V(V) for ion-exchange separation. The complex of V(V) and MB could be trapped by ion-exchange resin at pH 3.0 and eluted by 1.0?mol?L?1 NaOH. The vanadium species was determined subsequently by GFAAS. The concentration of V(IV) was calculated by subtracting the V(V) concentration from the total concentration of vanadium. Under the optimized experimental conditions, the detection limit of V(V) is 0.48?µg?L?1 with RSD of 2.6% (n?=?5, c?=?2.0?µg?L?1). In order to verify the accuracy of the method, a certified reference soil sample was analyzed, and the results obtained were in good agreement with the certified values. The range of recovery for V(IV) and V(V) was 97.8–99.3% and 101.7–103.6%, respectively. The proposed method was applied to the speciation analysis of vanadium in lake-water samples.  相似文献   

19.
Lai Y  Lin R  Cai L  Ge X  Huang C 《色谱》2012,30(1):21-26
建立了丙烯酸树脂中9种残余单体(丙烯酸甲酯、丙烯酸乙酯、甲基丙烯酸甲酯、甲基丙烯酸乙酯、丙烯酸丁酯、甲基丙烯酸丁酯、苯乙烯、丙烯酸、甲基丙烯酸)的微波辅助萃取-气相色谱-质谱检测方法。固体丙烯酸树脂样品用乙酸乙酯微波萃取后加甲醇沉淀(液态丙烯酸树脂样品直接用甲醇稀释)后,采用DB-WAX毛细管柱分离。结果表明,本方法在20 min内同时分离了9种单体,所测物质的定量限(LOQ,以信噪比为10计)为3~50 mg/kg(固体树脂)和1~10 mg/kg(液态树脂);在1~500 mg/L范围内,线性相关系数均在0.995以上;在5个添加水平下平均回收率为84.4%~108.6%,相对标准偏差(n=6)为0.27%~4.97%。方法的灵敏度和回收率高、选择性好,能满足实际工作的要求。  相似文献   

20.
A new epoxy-tannin chelating resin was synthesized from epoxy resin and used for the preconcentration and separation of rare elements. The acidity, rate, reuse, capacity and interference on the adsorption of ions on the resin as well as the conditions of desorption of these ions from the resin were investigated by means of inductively coupled plasma atomic emission spectrometry (ICP-AES). The composition of the resin and mechanism of enrichment for some ions were discussed. The results show that the relative standard deviations for the determination of 50 ng ml−1 Ga(III), In(III), Bi(III) and Sn(IV), 10 ng ml−1 La(III), Y(III), Cr(III), Ti(IV) and V(V) and 1.0 ng ml−1 Be(II) were in the range of 0.5–4.5%. The contents of these elements in a sample solution from a smelter determined by the new method were in agreement with those values obtained by Zeeman atomic absorption spectrometry with an average error <3.4%.  相似文献   

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