STUDIES ON POLYVINYL ALCOHOL CARRIERS Ⅲ. ACTIVE AMIDES AND ESTERS DERIVED FROM POLYVINYL ALCOHOL AND THEIR APPLICATION IN AFFINITY CHROMATOGRAPHY

Polyvinyl alcohol carriers bearing active amide and active ester groups were prepared by acetaliza-tion of granular macro-reticular water-insolub1e PVA with glyoxylic acid or p-formylbenzoic acidand further activation reaction with benzotriazole or N-hydroxysuccinimide using DCCI as con-densation agent. The active amides or active esters obtained were easy to react with amines suchas n-butylamine or proteins under mild condition. Ovomucoid, an inhibitor of trypsin was immo-bilized on the above-obtained reactive PVA carrier to give effective affinity adsorbent for the separa-tion or purification of trypsin.     

聚乙烯醇载体的研究 Ⅲ.由聚乙烯醇衍生的活性酰胺和活性酯及其作为亲合色谱载体的应用

<正> 亲合色谱法在现代生物学和医学上作为新的得力分离分析手段而方兴未艾。合色谱法是将相互在生物学上具有特异亲合力的某一化合物作为固定相接在水不溶性载体上,利用对此固定相的亲合力的差异以分离提纯另一化合物为目的的方法。常用的水不溶性载体如天然纤维素,葡聚糖凝胶,琼脂糖凝胶等或因成型不易,或因对酸,霉菌等的不     

双波长吸光光度法同时测定饮用水中钙和镁

研究了以偶氮胂Ⅲ作显色剂 ,用双波长吸光光度法同时测定水中钙和镁的最佳条件。测定钙和镁的最佳波长对分别为 6 5 0～ 5 93nm和 6 15～ 6 6 5 .5nm ,服从比耳定律的线性范围分别为0～ 12 μg/ 2 5ml和 0～ 18μg/ 2 5ml,检出限分别为 0 .0 1和 0 .0 18μg·ml- 1,加标回收率分别在 97 2 %～ 10 4 .5 %和 89.8%～ 92 .8%之间。将此法应用于饮用水中钙和镁的测定 ,结果满意。     

SYNTHESIS AND POLYMERIZATION OF ALIPHATIC TERTIARY AMINO-GROUP N-SUBSTITUTED ACRYLAMIDES

Aliphatic tertiary amino-group N-substituted acrylamides, N-acryl-N′-methylpiperazine (AMP)and N-methacryl-N′-methylpiperazine (MAMP) were synthesized directly from N-methylpiperazinewith corresponding acryloyl chlorides and characterized by elementary analysis of their picrates,~1H-NMR, IR and MS. AMP did not polymerize with benzoyl peroxide (BPO), but could poly-merize with lauroyl peroxide (LPO). The rate equation of the polymerization was given as R_P=K_P [AMP]~(1.5)[LPO]~(0.5) and the overall activation energy of this polymerization system was 10.8Kcal/mol. The redox nature of LPO with the monomer itself was suggested. Even though AMP and MAMP hardly proceed the polymerization initiated with BPO, butunder lower concentration would form redox system with BPO to initiate the polymerization of MMAreadily. The rate equation of the polymerization of MMA initiated with MAMP-BPO systemwas given as R_P=K_P [MMA] [MAMP}~(0.5) [BPO]~(0.5) and the overall activation energy was 10.2Kcal/mol. The analysis of the obtained polymers confirmed that MAMP not only initiated the poly-merization of MMA by combining with BPO, but also took part in the polymer chains impartingthem with better biocompatibility.     

固相净化-涡旋辅助-温控相变-离子液体液液微萃取高效液相色谱法同时测定大豆蛋白饮品中三嗪和苯脲类除草剂

建立了一种快速、高效、绿色的固相净化-涡旋辅助-温控相变-离子液体液液微萃取技术,结合高效液相色谱,同时测定大豆蛋白饮品中6种三嗪和苯脲类除草剂,包括灭草隆、绿麦隆、阿特拉津、绿谷隆、扑灭津和扑草净。本研究采用疏水性低密度固态季膦盐离子液体([P_{4 4 4 12}]BF₄)作为萃取剂,通过固相净化除去样品中的蛋白质和脂肪等杂质,经水浴和涡旋促进离子液体在样液中的分散,并通过控制温度,使离子液体由液态转变为固态,从而实现离子液体与样液的分离,达到萃取分析物的目的。优化了离子液体种类及用量、净化剂种类及用量、盐的用量、涡旋时间以及pH值等实验条件。6种目标物在各自的线性范围内具有良好的线性关系(R≥0.9994),检出限和定量限分别为0.52～2.59μg/L和1.72～8.63μg/L,加标回收率为82.6%～118.2%。本方法简单高效、绿色环保、试剂用量少,适用于大豆蛋白饮品中三嗪和苯脲类农药残留的提取与测定。     

利用沉积物和水体的环境DNA检测鱼类物种多样性的差异

环境DNA(environmental DNA,eDNA)调查因其敏感且能提供高分辨率的群落组成数据,正越来越多地被用于生物多样性的监测.但环境DNA研究评估不同的环境样本类型如何影响物种的可检测性仍然很少.在此,我们利用线粒体细胞色素b基因的环境DNA宏条形码比较了鄱阳湖中沉积物和水体的鱼类群落组成.结果显示:沉积物...     

近红外光谱法测定蜂蜜中主要成分的可行性研究

以153个单植物源和混合植物源蜂蜜样品为研究对象,使用３种近红外光谱仪(FT型、CCD型、PDA型)采集蜂蜜的透反射和透射光谱,并应用近红外定量分析技术进行蜂蜜中主要成分(水分含量、果糖含量、葡萄糖含量)的检测研究。用偏最小二乘回归(partial least square repression, PLSR)方法分别建立了蜂蜜水分含量、果糖含量、葡萄糖含量的近红外定量分析模型。结果表明,水分含量、果糖含量、葡萄糖含量的相关系数(r)分别达到0.978 5, 0.931 1和0.890 7,预测误差均方根(RMSEP)分别为0.410 8(%), 1.914 4(%)和2.531 9(%)。研究表明基于近红外光谱的蜂蜜主要成分快速无损检测准确度高,具有很高的实用价值。     

入口节流微通道换热器内相变传热特性

设计加工一种带有入口节流结构的铜基微通道换热器,理论分析其传热模型、实验测量微通道换热器内相变换热的传热特性和压力特性。结果表明:换热器内部的热传递过程为其主要换热模式;换热器表面温度随加热热流密度的增大而增大;微通道入口流速对表面温度影响较小;入口工质过冷度线性影响换热器的表面温度。热流密度在不同阶段对换热系数有不同影响,热流密度为360 W/cm~2时,换热器换热系数出现最大值;换热器压降随热流密度和系统流速的增加而增大。     

MXene/NR纳米复合材料的制备及性能研究

MXene是一种由MAX(Ti3 C2 Tx)相材料制成的新型金属碳化物和氮化碳二维晶体,因其轻质及高导电性和高机械性能而得到广泛应用.本文选用HF刻蚀Ti3 C2 Al制备出层状MXene,采用乳液共混法制备MXene/天然橡胶(NR)纳米复合材料,考察了MXene用量对MXene/NR纳米复合材料力学性能和耐磨性能...