离子交换树脂对白扦中莽草酸的分离纯化

建立了离子交换树脂分离纯化白扦中莽草酸的工艺条件和参数。通过研究D261、D296、D301-R、D301-G、D290、201*7(717)、D201和D280共8种离子交换树脂对莽草酸的吸附和解吸附能力,筛选出最佳树脂为D290,确定了最佳的吸附与解吸附工艺参数,吸附条件为pH=6、25 ℃、流速为3 mL/min;脱附条件为：洗脱液为2.5%NaOH水溶液,洗脱流速为3 mL/min。莽草酸样品溶液经D290树脂吸附与脱附后回收率为92.53%,纯度由2.97%提高到46.76%,提高了15.74倍。实验结果表明,D290树脂对莽草酸的吸附量大,脱附容易,可以应用于莽草酸的分离纯化。     

D301阴离子交换树脂吸附2-酮基-L-古龙酸母液中草酸的研究

研究了分离出2-酮基-L-古龙酸母液中的草酸时,D301阴离子交换树脂在静态和动态情况下吸附草酸的过程,并利用Freundlich吸附等温方程对吸附等温线数据进行拟合。结果表明:D301树脂对草酸的平衡吸附数据符合Freundlich吸附等温方程,在293、303、313K三种温度下相关系数均大于0.99;且在pH值为6、温度313K、流速30mL/min时吸附量达到最大。这些研究为从古龙酸母液中除去或者回收草酸找到了一种有效的方法,并且可降低母液的COD值,从而降低污染。     

2,4-二羟基苯甲酸在3种树脂上的吸附特性

通过静态和动态吸附实验, 研究了717(凝胶型,强碱)、D201(大孔型,强碱)和D301R(大孔型,弱碱)3种阴离子交换树脂对水溶液中2,4-二羟基苯甲酸的吸附特性. 结果表明,717和D201在pH 4~11时、D301R在pH 3~9时吸附能力最好. 在pH=5及温度293~313 K、初始浓度0.6488~6.488 mmol/L条件下,D301R, 717和D201对2,4-二羟基苯甲酸的等温吸附规律均符合Freundlich模型,最大平衡吸附量分别为2.98, 2.66和2.54 mmol/g(吸附未达饱和),均为物理性自发吸附的放热过程. 动力学实验数据用准一级模型方程拟合比准二级更接近实验值. 5%(w) NaCl+2%(w) NaOH脱附液100 mL均可有效洗脱3种树脂上吸附的2,4-二羟基苯甲酸,脱附率达99%. 相同条件下,D301R树脂对2,4-二羟基苯甲酸的吸附性能优于D201和717树脂.     

大孔树脂对刺五加中总黄酮吸附研究

通过比较5种不同极性的大孔树脂对刺五加中总黄酮的吸附性能,筛选出吸附效果最佳的树脂,对其进行静态吸附研究。并进一步通过吸附过程的热力学和动力学研究其吸附规律。结果表明,D301R树脂吸附效果最好,在25℃、5 h、固液比为3:40的条件下,吸附量能达到56.89 mg/g。根据动力学结果,其吸附过程更符合准二级动力学。通过采用Freundlich和Langmuir等温吸附方程进行拟合不同温度下D301R大孔树脂对刺五加中总黄酮的吸附过程,Langmuir等温吸附模型拟合度更高,说明该吸附为单分子吸附。     

新型阳离子交换树脂D301-g-PSSS的制备及其对金属离子的吸附性能

利用D301树脂表面的氨基与过硫酸铵构成氧化–还原引发体系,实现了单体对苯乙烯磺酸钠在D301树脂表面的接枝聚合,制得D301树脂表面接枝聚对苯乙烯磺酸钠(PSSS)(D301-g-PSSS)吸附材料。采用傅立叶变换红外光谱对D301-g-PSSS进行了表征,并用称重法和滴定法测定了其接枝率,在适宜条件下的接枝率分别达到17.7%,17.3%。考察了D301-g-PSSS对Al3+,Cu2+,Fe3+的吸附性能。D301-g-PSSS对3种金属离子具有很强的吸附能力,最大吸附容量可分别达到13.285,14.864,15.10 mg/g。3种金属离子的等温吸附符合Langmuir等温吸附模型,平衡吸附容量随着pH值的增大而增大,随着温度的升高而减小。D301-g-PSSS具有较好的重复利用性,重复使用6次D301-g-PSSS吸附Fe3+,其吸附容量变化不大。     

啶虫脒和苯胺双组分在树脂上的竞争吸附行为

[目的]研究水溶液中啶虫脒和苯胺双组分在树脂上的吸附行为、树脂对2组分的吸附选择性。[方法]以啶虫脒/苯胺为吸附质,以D201和ZH202树脂为吸附剂,研究啶虫脒和苯胺在单组分、双组分水溶液中2种树脂上288、303、313 K温度下的吸附行为。[结果]2种吸附剂对单组分2种吸附质的吸附等温线符合Freundlich方程,苯胺和啶虫脒在2种吸附剂上吸附过程均为放热过程。[结论]啶虫脒和苯胺双组分共存吸附体系下,呈现竞争吸附现象。     

大孔树脂分离发酵苹果酸的静态吸附工艺研究

通过5种大孔树脂对苹果酸吸附量的比较,其中阴离子树脂D301G吸附率最大。据此探讨了的D301树脂在不同时间、发酵液浓度、转速、pH、温度等影响因素下对静态吸附容量的影响。最终确定最佳操作条件为:转速150r/min、温度37℃、pH为5、吸附时间2 h、发酵液浓度10%。     

离子交换树脂法提纯维生素C磷酰化反应液

采用D301大孔弱碱阴离子交换树脂分离提纯维生素C磷酰化反应液.测定了室温下D301树脂吸附维生素C磷酸酯钠的动力学曲线和吸附等温线,考察了溶液pH值、温度、盐酸洗脱液浓度等因素对吸附的影响.最后用D301树脂对磷酰化反应液进行梯度洗脱,并用HPLC进行分析.结果表明D301树脂吸附维生素C磷酸酯钠约60 min达到平衡,Freundlich方程可以较好地描述树脂对维生素C磷酸酯钠的吸附.在室温下将磷酰化反应液调节pH至1～2后上柱吸附,依次用0.05 mol/L、0.2 mol/L、2.0 mol/L的盐酸溶液洗脱,收集0.2 mol/L盐酸洗脱液,用HPLC分析,结果其维生素C磷酸酯含量大于97%.     

离子交换树脂脱除高浓磷酸钠溶液中的钒(V)和铬(VI)

采用静态吸附实验研究了离子交换法深度脱除高浓度Na3PO4水溶液中微量钒(V)和铬(VI),考察了树脂性质、吸附温度、吸附pH值和固液比对钒(V)、铬(VI)吸附的影响. 结果表明,在5种大孔苯乙烯系树脂中,D301R最适合脱除高浓磷酸钠溶液中的钒(V)和铬(VI),料液pH 6.5、室温、树脂/料液比1 g/10 mL时,钒(V)、铬(VI)的去除率较好. 10次动态循环实验结果表明,钒、铬脱除效率均在90%和80%以上,树脂重复使用性能稳定. 钒在D301R树脂上的吸附主要受其与磷的置换过程控制,且其在树脂中的传质速率低于铬.     

D301树脂吸附废水中草甘膦的研究

通过静态实验探究了吸附剂用量、氯离子浓度、磷酸盐浓度对D301树脂吸附废水中草甘膦的效果影响,同时研究了该吸附过程的动力学、等温线。结果表明,废水中草甘膦氯离子和磷酸盐浓度越高,D301树脂吸附效果越差,草甘膦去除率越低。该吸附过程符合Langmuir方程,为单层吸附,最大吸附量约为181.8 mg/g,符合二级动力学模型。动态实验结果表明,当D301树脂吸附草甘膦达到穿透体积时,草甘膦去除率为79.3%。     

Fatty acid monoesters of 1-ascorbic acid and d-isoascorbic acid

Summary Fat-soluble fatty acid monoesters of 1-ascorbic acid (vitamin C) and d-isoascorbic acid have been prepared from lauric, myristic, palmitic, and stearic acids in 40–50 per cent yields. Evidence has been presented to show that only the primary hydroxyl group of each of the ascorbic acids has been esterified. Antioxidant properties of these esters are being studied. Preliminary tests on the esters have indicated that they may have useful properties as interfacial modifiers.     

Electrosynthesis of 2,3-dimethyltartaric acid from pyruvic acid in acid medium

This study reports the electrohydrodimerization of pyruvic acid to 2,3-dimethyltartaric acid in sulphuric acid medium (0.5 M H₂SO₄) on a lead cathode. The main products detected were lactic acid and 2,3-dimethyltartaric acid. The selectivity towards the formation of 2,3-dimethyltartaric acid was studied vs. pyruvic acid concentration in sulphuric acid solution, at −1.1 V vs. MSE. The best selectivity of 2,3-dimethyltartaric acid reached 69% for an initial concentration of 1.7 M pyruvic acid. The yield of pyruvic acid was 84%.     

乳酸催化制备丙烯酸反应液中乳酸和丙烯酸含量的联合测定

以正丁醇为内标,氢火焰离子化检测器测定,建立了气相色谱法直接进样测定乳酸催化制备丙烯酸反应液中乳酸和丙烯酸含量的方法。在载气（N2）流速为30mL·min^-1,氢气流速为88mL·min^-1,空气流速为300mL·min^-1,进样器和离子室温度为160℃,柱温为150℃的10％PEG-20M（3m×3mml填充柱上能实现很好的分离。乳酸和丙烯酸测定方法的线性相关系数分别为0．9994和0．9996,相对标准偏差分别为O．74％和0．56％,平均回收率分别为97．35％-1197．60％,检出限分别为8．62mg·L^-1和1．21mg·L^-1方法简便、快速、准确。     

Electrosynthesis of iminodiacetic acid from nitrilotriacetic acid

The electrosynthesis of iminodiacetic acid by electrooxidation of nitrilotriacetic acid in undivided cells has been studied using Zn, Cu, PbO₂, DSA^®O₂, DSA^®Cl₂, C, Ni and porous carbon as anodes. Results show that the synthesis is possible in both acid and basic mediums. The best results were obtained in aqueous 40% w/w sulphuric acid with porous carbon RVC-4000 as anode and SUS 316 as cathode, at 60 °C, 400 mA cm^-2 and charge 95% of theoretical. Under these conditions, nitrilotriacetic acid conversion was 92%, current efficiency 80% and selectivity 85%. Loss of selectivity was due to chemical side reaction between iminodiacetic acid and HCHO electrogenerated in the electrolysis.     

The performic acid oxidation of linoleic acid

The performic acid oxidation of linoleic acid has been shown to form 9,12-dihydroxy-trans-10,11-methylene-heptadecanoic acid (I) after hydrolysis of the formate ester. A sequence of reactions led to the identification of dimethyl-trans-1,2-cyclopropanedicarboxylate by gas liquid chromatography. Spectroscopic evidence is presented for thetrans geometry in I. Failure of the monoepoxide of linoleic acid to give the formate ester of I suggests the alternative that a homoallylic carbonium ion is formed directly upon attack of the peroxide reagent.     

由氯乙酸副产盐酸精制高纯盐酸

开发研究了氯乙酸副产盐酸的精制工艺及盐酸中有机杂质的紫外分光光度分析方法。副产盐酸经酸洗、吸收、蒸馏得高纯盐酸。中试结果表明 ,工艺合理 ,精制盐酸达到GB 32 0 - 93规定的工业用合成盐酸标准     

液相色谱法测定氯乙酸中乙酸、二氯乙酸的含量

提出了液相色谱法测定氯乙酸中乙酸和二氯乙酸含量的分析方法,计算出氯乙酸的含量,并与现行工业氯乙酸国标分析方法进行了比较,证明液相色谱分析方法简洁、快速,分析结果准确,在氯碱行业具有推广运用的价值。     

次磷酸、亚磷酸、正磷酸联合生产新工艺

在作者开发的高速反应器一步法制专用级次磷酸钠的基础上进一步将生成的次磷酸钠和副产的亚磷酸氢钙用离子膜电渗析法制成纯度更高的次磷酸及亚磷酸产品,产品质量升级,回收利用了副产亚磷酸氢钙,并减少了原料烧碱的用量。该新工艺成本低,能耗小,无三废排出,产品多样化,属循环经济、环境友好新工艺。     

Characterization of dihydroxystearic acid from palm oleic acid

Dihydroxystearic acid (DHSA) was prepared from palm oleic acid and characterized by chromatographic and spectroscopic methods (gas chromatography, thin-layer chromatography, Fourier transform infrared and nuclear magnetic resonance spectroscopy) as well as wet chemistry. The crude product has a melting point of 62°C, acid value of 179, saponification value of 178, and hydroxyl value of 196. The yield was about 90% based on unsaturation. The product obtained was found to contain DHSA, saturated fatty acids, and unknown products. DHSA is soluble in alcohol, and its solubility decreased by increasing the alcohol chain length. An irritancy test of DHSA indicated that purified DHSA is nonirritating.