大孔树脂对紫甘薯色素的吸附与解吸特性研究

为了选择紫甘薯色素粗提液纯化性能较好的树脂,采用AB-8型、S-8型、NKA-II型和NKA-9型4种大孔树脂对紫甘薯色素进行了吸附与解吸试验,研究了大孔树脂对紫甘薯色素的静态吸附动力学曲线、吸附等温曲线及解吸特性。结果表明：在4种树脂中,AB-8型树脂吸附平衡的速率常数为最大,对紫甘薯色素的吸附量和解吸量分别是S-8、NKA-II及NKA-9的119%,139%,118%和105%,116%,118%,因而AB-8型大孔树脂是用于纯化紫甘薯色素较为合适的吸附剂,解吸时宜选用60%乙醇溶液。     

大孔树脂法纯化红花芸豆色素及初步鉴定

该文通过静态吸附和解吸实验,选择了合适的大孔树脂纯化红花芸豆色素,优化了吸附和解吸条件,并应用纸色谱法和紫外—可见光谱法对纯化后的色素进行了初步的分离鉴定。结果表明,HPD400型大孔树脂对pH值为1的红花芸豆色素酸提液吸附率为88.38%,pH值2的75%乙醇可较好的洗脱色素。纯化后色素有2个主要成分,初步鉴定为天竺葵定-3-葡萄糖苷和芍药定-3-葡萄糖苷。     

树脂法精制沙棘籽原花色素的研究

为纯化沙棘原花色素,本文对16种不同类型树脂进行沙棘原花色素静态吸附试验、动态吸附和解吸性能的比较,筛选出对沙棘原花色素有较好分离纯化效果的4种树脂,比较不同洗脱级分中原花色素的含量,最后筛选出D3520大孔树脂为符合提纯要求的最适合的树脂;采用该树脂,用30%乙醇洗脱,原花色素产品纯度达96.5%,得率为30.4%。     

芹菜黄酮在LSA-10树脂上的吸附特性

为了分离、纯化芹菜黄酮,比较了8种大孔树脂的静态吸附过程,筛选出了适合吸附芹菜黄酮的树脂;研究了芹菜黄酮在大孔吸附树脂上的动态吸附特性,并确定分离芹菜黄酮的适宜工艺条件.结果表明:LSA-10大孔吸附树脂对芹菜黄酮有较好的吸附分离性能,其对芹菜黄酮的静态吸附平衡时间为4 h;20℃时LSA-10树脂的吸附过程可用Langmuir吸附等温式来描述,吸附溶液适宜的pH值为5.0.操作流速、芹菜黄酮浓度、温度等工艺条件对LSA-10树脂的动态吸附动力学曲线都有影响:确定树脂柱的较佳操作条件为:流速1.0 mL/min,芹菜黄酮浓度0.4 mg/mL,温度20℃.     

D315树脂分离茶多糖工艺的研究

对D315树脂分离纯化茶多糖的工艺进行了研究,试验结果表明,D315树脂适合用于茶多糖的初步分离和纯化。在上样液pH值6.0～7.0,温度30℃,糖醛酸质量浓度2.5 mg/mL时,先收集上柱吸附的流出液和去离子水洗脱液,得到以中性糖为主的茶多糖NTPS,该多糖总糖质量分数为82.7%,糖醛酸质量分数为7.9%;而后采用0.5 mol/L NaCl溶液洗脱,得到糖醛酸含量高的酸性糖ATPS,该多糖总糖质量分数为85.5%,糖醛酸质量分数为35.2%。     

离子交换和吸附相结合抑制浓缩酥梨汁褐变的研究

该文研究离子交换和吸附相结合技术在降低、控制浓缩砀山酥梨汁褐变中的应用。将20 °Brix砀山酥梨汁依次经FPC-21阳离子交换树脂和XAD-16大孔吸附树脂处理后,减压浓缩至70 °Brix,贮存,检测褐变指数等指标的变化。结果显示,阳离子树脂处理可降低酥梨汁的pH值、氨基态氮和褐变指数;降低pH值可提高吸附树脂对酥梨汁的脱色能力;降低pH值、氨基态氮可控制70 °Brix浓缩酥梨汁贮存中褐变速度。采用阳离子树脂处理将酥梨汁的pH值降低为4.05,再经吸附树脂将色值提高为85%,浓缩至70 °Brix的酥梨汁在37℃下贮存35 d后,色值仍大于45%,符合出口要求。     

大孔树脂分离纯化柚皮黄酮的研究

该文以总黄酮含量和总黄酮回收率为考察指标，研究了大孔树脂分离纯化柚皮黄酮的工艺。结果表明：AB-8型树脂对柚皮总黄酮有较好的吸附分离性能，是分离纯化柚皮黄酮的适宜大孔树脂；AB-8型大孔树脂分离纯化柚皮黄酮的最佳工艺条件为：柱体积为160 mL，柚皮提取物上样量为62.5 mg/mL(以湿树脂体积计)，先用pH 4的水淋洗，再用30%的乙醇洗脱，洗脱剂用量为2.5～3倍湿树脂体积。AB-8大孔树脂按上述确定的吸附洗脱条件可重复使用3次。柚皮黄酮经上述工艺纯化后总黄酮含量达到39.67%，总黄酮回收率为62.48%。对经AB-8大孔树脂纯化后的柚皮黄酮进行高效液相色谱(HPLC)分析发现，柚皮黄酮主要为黄酮甙类。     

黑青稞麸皮结合态酚类物质大孔树脂分离纯化工艺优化

为了筛选对黑青稞麸皮结合酚类物质具有良好吸附、解吸性能的树脂,并建立其分离纯化工艺,评价其体外抗氧化活性,提高黑青稞麸皮的加工利用价值。本研究通过静态吸附和解吸试验比较了10种大孔树脂对黑青稞麸皮结合酚中总酚和总黄酮的分离纯化效果,筛选出AB-8为最佳吸附树脂类型,其静态吸附4 h可达到饱和;优化的吸附和解吸工艺参数为：黑青稞麸皮结合酚提取液pH值为3.0,上样质量浓度1.5 mg/mL,上样速度为1.5 mL/min,60%乙醇溶液作为洗脱剂进行动态洗脱,洗脱流速为1.5 mL/min;优化工艺条件下,经LC/MS检测,AB-8大孔树脂能显著提高71.43%以上不同种类单体酚的含量,且阿魏酸、丁香酸、苯甲酸、鞣花酸、杨梅素和芦丁是纯化后黑青稞麸皮结合酚中的主要酚类物质;体外抗氧化活性表明,黑青稞麸皮结合酚粗提物和纯化物均具有较强的体外抗氧化活性,纯化后的黑青稞麸皮结合酚溶液清除DPPH·、ABTS·+自由基及FRAP铁离子还原能力均显著增强。研究结果表明AB-8大孔树脂对黑青稞麸皮结合酚中总酚和总黄酮有较好的分离纯化效果,具有潜在的工业应用前景。     

大孔树脂对苹果渣中多酚物质的吸附研究

通过静态吸附与解吸实验对8种大孔树脂进行筛选,结果表明:NKA-9型大孔树脂表现出最好的吸附性能与解吸效果,是较好的富集纯化苹果多酚树脂。通过单因素实验，确定NKA-9树脂的较佳动态吸附条件为苹果多酚液浓度2.50 mg/mL，pH 4.5，流速1.0 mL/min，较佳洗脱条件为乙醇浓度60%,洗脱流速1.0 mL/min,洗脱体积10 BV。     

吸附树脂吸附蜂蜜中羟甲基糠醛的热力学研究

为考察大孔吸附树脂对蜂蜜中羟甲基糠醛(HMF)的吸附可行性，该文采用静态吸附法研究了LSA-800B型大孔树脂对HMF吸附过程的热力学性质。结果表明，在298，308，318 K和研究的浓度范围内，蜂蜜中的HMF在LSA-800B型树脂上的吸附等温线均符合Freundlich等温吸附方程，Freundlich吸附等温线和等量吸附焓表明LSA-800B型树脂对蜂蜜中HMF吸附是放热过程。吸附自由能ΔG＜0表明吸附的自发性，吸附熵变ΔS＜0说明吸附质分子在吸附树脂表面上的运动比在溶液中受到更大的限制。     

Sensitivity of Soil P Availability Tests to Ca-P in Oxisols

We assessed the sensitivity of mixed exchange resin (MER) and Mehlich-3 (M3) to calcium-bound phosphate (Ca-P) in Oxisols. These methods were compared with Mehlich-1 (M1) and anion exchange resin (AER), which have high and low sensitivity, respectively, to this soil P form. We used maize (Zea mays L.) as a test plant. Three samples from two Oxisols were treated with five ratios of Triple Superphosphate—TS and Bayóvar Phosphate Rock—BPR (0 + 100; 25 + 75, 50 + 50, 75 + 25 and 100 + 0% TS + BPR). The MER extracted more P than AER and M3 at the highest BPR:TS ratios (high Ca-P) and similar quantities at the higher TS:BPR ratios (low Ca-P) for two soil samples. Unlike M1-extracted P, M3-P, AER-P, and MER-P positively correlated with maize dry matter production and P uptake. Mehlich-3 and MER were suitable to assess P availability in high Ca-P Oxisols.     

阴离子交换树脂固定化果胶酶及其酶学性质的研究

以阴离子交换树脂为载体,戊二醛为交联剂,对果胶酶进行先吸附后交联的固定化,研究吸附温度、吸附pH值、吸附时间、加酶量、戊二醛浓度、交联温度、交联时间对果胶酶固定化效果的影响,同时对固定化果胶酶的特性进行了研究。研究表明,最佳固定化条件为:温度40°C,pH 5.5,固定化6 h,加酶量0.75 mL/g树脂(浓度为1%酶液),戊二醛交联浓度0.1%,交联温度4°C,交联时间4 h。酶学特性研究表明,固定化果胶酶在最适温度60°C,最适pH 4.0下具有较好的操作稳定性。     

Assessing the Role of Competing Anions Silicate and Bicarbonate on Diffusion of P vis-à-vis Its Bioavailability in Different Soils Measured by Resin Disc Technique

The bioavailability of phosphorus (P) depends on its diffusion process. An attempt has been made to study the effects of bicarbonate and silicate on phosphate diffusion through the analysis of its bioavailability. Resin discs were used to determine P diffusion rate (PDR), which was observed to increase in the presence of competing anions in the following sequence: silicate > bicarbonate > control. Phosphorus diffusion rate also increased with added P levels, temperature, and moisture. Added P level in soil is the most important factor, which contributed about 56% of the variation in PDR. The presence of competing anions such as bicarbonate and silicate accounted for 12.5% of the variations of PDR in soil system. Embedded resin discs in fields treated with different treatments showed significant variation of PDR in the following sequence of treatments: mixture of biogas slurry and paddy straw > sodium silicate > only paddy straw > biogas slurry > control.     

Measuring interlayer potassium release rates from soil materials. I. Critical evaluation on the use of resin and other batch procedures for determining kinetic data

Laboratory procedures are evaluated for their principal suitability to derive unbiased kinetic data of interlayer K release (days to weeks, Luvisol ‘Ohlendorf’, loess, Ap horizon). The final intention is to relate K release rates to their main governing soil environmental variables rather than to conventional procedural standards. Of actual interest are technical aspects of quantifying the influence of solute K (C_K), which is considered to be the most important among those variables. The relevant range is that of a few μM K, similar to the rhizosphere of plants where diffusion-controlled, non-destructive K release is thought to be of importance. Tested non-resin batch techniques, e.g. the time dependent shift of K-Ca exchange isotherms, are considered to be unsuitable because the derived release rates were markedly biased by shaking the suspensions. Generally, the batch technique just showed that additional proton induced release of nonexchangeable K (K_nex) is negligible above pH 4. Ca-resin procedures extracted considerable amounts of K_nex but most of it had to be attributed to the addition of fresh (K-free) exchange solution rather than to the presence of the resins. Further, an active regulation of C_K in the intended range was only hardly possible via the resin/soil ratio but was inexact and only achieved with inacceptable effort. Further modifications, e.g. containing the resins in dialysis tubes, improved the technique but did not eliminate the main problems: Ca-resin does not act as a real sink for K. H-resins did act as a sink but, due to other constraints, are also rejected: C_K is too low (< 1 μM, no effective regulation possible) and the pH of the suspension steadily declines (< 3 after one week). The one promising procedure among those tested was a continuous (non-resin) percolation technique (> 900 h) which permitted a flexible regulation of C_K by the percolation rate.     

大孔吸附树脂分离纯化罗汉果皂甙的新方法

该文对大孔树脂分离纯化高含量罗汉果皂甙提取物的新方法进行了研究。结果表明：大孔树脂D101对罗汉果皂甙的分离效果较好,最佳柱分离条件为：上样液pH值9.0,在40℃下依次用pH值9.0的碱水溶液、蒸馏水、30%乙醇及60%乙醇进行洗脱,将60%乙醇洗脱液浓缩,冷冻干燥即得高含量罗汉果皂甙提取物。高效液相分析表明,罗汉果皂甙中几种主要成分的含量均高于分离前的罗汉果皂甙水提物,其中罗汉果皂甙V的含量为69.24%,提高了41.12%。     

木质素-苯酚-甲醛树脂胶黏剂的性能与合成机理

为了降低酚醛树脂的制备成本,该研究分别以30%、40%和50%碱木质素部分替代苯酚合成木质素-苯酚-甲醛（Lignin-Phenol-Formaldehyde, LPF）树脂胶黏剂,主要研究了其替代比对LPF树脂胶合性能、固化性能和热稳定的影响,同时探讨了LPF合成机理。结果表明：1）LPF树脂具有透明度低、固体含量大、游离甲醛较低、黏度大导致活性期短和施胶困难的特点。2）LPF制备的胶合板胶合强度随碱木质素增加呈先增加后减小的趋势,但均高于PF树脂,碱木质素取代苯酚量最大可达50%。3）DSC分析表明LPF树脂固化温度高,且随碱木质素添加量增加而升高。4）碱木质素加量过高或过低都会影响LPF的热稳定性,为40%时的热稳定性高于PF树脂。5）碱性条件下,无论是以苯酚、木质素酚环还是木质素侧链为反应起点合成LPF,羟甲基苯酚经E1cb反应机理形成亚甲基共轭结构,是合成LPF的关键。该研究工作的开展可为LPF合成工艺改进和实际应用提供进一步的科学指导。     

LSA—800B吸附树脂对苹果汁吸附脱色的动力学研究

该文研究了不同温度(25℃～70℃)和不同树脂浓度(1，2，4，8 g/L)条件下LSA—800B树脂对苹果汁吸附脱色的动力学过程。试验结果表明，该树脂吸附平衡曲线符合Langmuir和Freundlich模型，获得了不同温度下的模型参数值(K_ad、Q₀、K_f和n)。吸附焓变化(ΔH)值为4.16 kJ/mol说明这一过程是吸热过程。自由能(ΔG)随温度升高而呈下降趋势说明此过程是自发过程。由试验数据进一步计算出了不同树脂浓度和不同温度下苹果汁吸附脱色的动力学参数。随着温度升高吸附能力提高，但初始平衡时间有所减少；在2～4 g/L的树脂浓度范围内，吸附效果比较明显，在55℃时，树脂达到初始平衡的覆盖率(θ_e)较高，据此确定了该树脂对苹果汁吸附脱色的适宜温度和树脂浓度范围分别为55℃，2～4 g/L。     

Release Rates of Ammonium‐Nitrogen,Nitrate‐Nitrogen,Phosphorus, Potassium,Magnesium, Iron,and Manganese from Seven Controlled‐Release Fertilizers

Abstract

Samples of seven controlled‐release fertilizers, Nutricote Total 13–13–13, Nutricote Total 18–6–8, Osmocote Plus 15–9–12, Osmocote 13–13–13, Polyon 18–6–12, Polyon 14–14–14, and Plantacote 14–8–15, were placed in leaching columns containing acid‐washed sand. Samples of all leachates were analyzed weekly to determine release rates of ammonium‐nitrogen (N), nitrate‐N, phosphorus (P), potassium (K), magnesium (Mg), manganese (Mn), and iron (Fe). Release rates for P from all products were slower than those for NH₄‐N, NO₃‐N, and K. Release of Mg, Mn, and Fe was very poor, with less than 50% of the total amount of each of these elements ever being released from the prills for some products. Nutricote products released Fe and Mn more effectively than did Osmocote or Plantacote.