蚕沙制备糊状叶绿素的工艺研究

在单因素实验的基础上,利用L9(34)正交试验法研究了蚕沙中叶绿素的提取工艺,通过分光光度计对各提取液中叶绿素的含量进行了检测。结果表明:以蚕沙质量4倍的95%丙酮为提取剂﹑在45℃下提取3.5h为最佳提取工艺,所得到的叶绿素含量最高。制备的糊状叶绿素,检验结果合格。     

微波预处理萃取蚕沙中叶绿素的研究

提出了微波辅助萃取蚕沙中叶绿素的新工艺,以少量的细胞破壁助剂作为蚕沙的润湿剂和微波能量接受体,对蚕沙中的叶绿素提取进行预处理,结果表明,经过微波处理过得蚕沙的叶绿素提取率较传统的提取方法提高25%,提取时间比传统提取时间节省80%,效果显著.     

分光光度法测定地表水中叶绿素a的进一步研究

本研究结合已有权威标准和相关报道,以安顺市饮用水源点的地表水为供试对象,探索并优化分光光度法测定地表水中叶绿素a的条件。研究主要通过改进叶绿素a的提取条件和改变比色皿长度来进行实验。研究结果表明：通过改进叶绿素a的提取条件和改变比色皿长度,可有效减少叶绿素a在提取过程中的损失,降低检出限,更准确地反应地表水中叶绿素a的含量。     

微波萃取甘蓝叶绿素工艺研究

以甘蓝叶为原料。利用微波辐射萃取法提取甘蓝中的叶绿素。以辐射时间、破壁助剂、乙醇浓度、料液比、提取时间、提取温度等作为影响因素进行单因素试验,通过分析确定了单因素的最佳实验条件。采用正交实验设计,优化甘蓝叶绿素的提取条件。结果表明：微波萃取甘蓝叶绿素的最佳工艺条件为乙醇浓度95％,提取时间50min,提取温度60℃,料液比1：12。与传统提取方法相比较,叶绿素的提取率可提高20％左右。     

超声波辅助混合溶剂提取蚕沙中叶绿素的工艺研究

以石油醚-丙酮混合溶剂为提取剂,采用超声波辅助法提取蚕沙中叶绿素,以叶绿素提取率为目标,对超声时间、超声温度、超声功率、固液比、助剂(丙酮)含量和提取次数进行优选研究。结果表明,最佳提取工艺为提取次数4次,助剂(丙酮)含量20%,固液比1∶4(g/mL),超声时间50 min,超声功率90 W,超声温度45℃。在此优化条件下,蚕沙中叶绿素提取率为90.6%。     

水体中叶绿素α测定方法的探究

在环境监测中,叶绿素α的测定方法主要参照《水和废水监测分析方法》(第四版)中的分光光度法,该方法存在测定结果误差大的问题,同时暴露在高浓度丙酮环境中,对分析者的健康有损害影响。在原始方法的基础上进行了免研磨法提取叶绿素α,实验结果表明:该方法对叶绿素α提取率的提高率可达53.4%~62.8%,有效避免了研磨过程造成的叶绿素α损失,同时发现随着提取时间的增加,叶绿素α的测定值增加,且提取8 h后增长的趋势开始趋于稳定。     

苦瓜叶绿素的提取和稳定性的研究

对苦瓜中叶绿素的提取方法及温度、pH、光照、氧化剂、还原剂、金属离子等对叶绿素稳定性的影响进行了研究.结果表明:选取丙酮:无水乙醇=1:1的混合溶剂为提取剂,浸提时间3h,液料比12:1,温度50℃作为苦瓜叶绿素的优化提取条件.该叶绿素具有较好的耐还原性,在pH=6～8的范围内稳定性较好,对常用的食品添加剂性质稳定,但热稳定性较差,只能在95℃范围内稳定,且在光照条件下会发生光降解现象.     

叶绿素衍生物制备有机颜料的研究

通过用丙酮浸渍的方法从菠菜中提取叶绿素,再采用铜化、皂化的方法将叶绿素制备成叶绿素铜钠,然后用钡离子进行色淀。实验结果表明,叶绿素铜钠色淀具有较好的耐热性能,在室内光照下也具有较好的色稳定性。     

蚕沙叶绿素废液中卷烟香料的提取及应用

为充分利用蚕沙叶绿素废液,并寻找一种新的天然卷烟香料的制备方法,采用同时蒸馏萃取法从提取叶绿素后的蚕沙废液中提取卷烟香料,并对提取得到的香料进行了挥发性成分分析和卷烟加香试验。结果表明,蚕沙叶绿素废液提取物中共鉴定出22种成分,主要为酮类和萜烯类等重要的烟草香味物质;蚕沙叶绿素废液提取物对提高卷烟香气质、增加烟气甜润度和回甜生津感、柔和烟气、减少杂气、改善余味有明显效果。蚕沙叶绿素废液提取物可作为一种新型天然香料用于卷烟加香。     

以羊蹄甲树叶制备叶绿素铜钠的工艺条件研究

由羊蹄甲树叶提取叶绿素并经皂化、铜代及成盐反应制备叶绿素铜钠,研究探讨了优惠提取工艺条件和反应条件。     

The effect of freezing on the analysis of chlorophyll content of canola seed (Brassica napus L.)

High levels of chlorophyll in harvested canola seed result in loss of revenue to producers and problems for processors. Studies on chlorophyll degradation often require plant material to be stored for some time prior to measuring the chlorophyll content. Storage of unripe canola seed in a freezer for up to one month prior to measuring the chlorophyll content did not alter the chlorophyll level in the seed. Seeds were frozen while still in the pods as well as after removal with no change in chlorophyll content over time.     

Antioxidant effects of chlorophyll and pheophytin on the autoxidation of oils in the dark. I. Comparison of the inhibitory effects

The effects of chlorophyll and pheophytin on the autoxidation of oils in the dark were investigated by oven tests. The results indicated that both chlorophyll and pheophytin show antioxidant activity when methyl linoleate is used as substrate. Furthermore, chlorophyll retarded the oxidative deterioration of triglycerides in rapeseed and soybean oils at 30 C. Among the four chlorophyll derivatives (chlorophylls a and b and pheophytins a and b), chlorophyll a showed the strongest antioxidant activity. The antioxidant effects of chlorophyll and pheophytin depended on the storage temperature and the kinds of oil used as substrate.     

海水叶绿素荧光测定仪的研制及性能研究

基于叶绿素荧光特性及原理,提出了一种叶绿素荧光检测方法,研制出了叶绿素现场荧光测定仪。实验中将叶绿素提取液配制成具有一定浓度梯度的稀释液,分别用叶绿素荧光测定仪、FL-7000荧光分光光度计和722型可见分光光度计同时对其进行测定并比较,结果表明叶绿素荧光测定仪具有较好的线性;对叶绿素荧光测定仪进行线性范围的测定,在440mV左右趋于平缓。     

Antioxidant effects of chlorophyll and pheophytin on the autoxidation of oils in the dark. II. The mechanism of antioxidative action of chlorophyll

To understand the mechanism of the antioxidant effect of chlorophyll on the autoxidation of oils in the dark, antioxidant activities of several derivatives of chlorophyll were compared. Antioxidant activities were observed in chlorophyll derivatives such as protopor-phyrin methyl ester and its magnesium chelated compound. Porphyrin seems to be an essential chemical structure for the antioxidant activity of chlorophyll. Chlorophyll did not decompose the hydroperoxides, but reduced free radicals such as 1,1-diphenyl-2-picrylhydrazyl. Electron spin resonance spectrum of the π-cation radical was recorded during the oxidation of chlorophyll in methyl linoleate solution. These observations suggest that chlorophyll may act as a hydrogen donor to break the chain reaction.     

Biologically inspired graphene-chlorophyll phototransistors with high gain

We present prominent photoresponse of bio-inspired graphene-based phototransistors sensitized with chlorophyll molecules. The hybrid graphene-chlorophyll phototransistors exhibit a high gain of 10⁶ electrons per photon and a high responsivity of 10⁶ A/W, which can be attributed to the integration of high-mobility graphene and the photosensitive chlorophyll molecules. The charge transfer at interface and the photogating effect in the chlorophyll layer can account for the observed photoresponse of the hybrid devices, which is confirmed by the back-gate-tunable photocurrent as well as the thickness and time dependent studies of the photoresponse. The demonstration of the graphene-chlorophyll phototransistors with high gain envisions a viable method to employ biomaterials for graphene-based optoelectronics.     

从苎麻叶中制取叶绿素铜钠

研究了从苎麻中提取叶绿素的方法, 并可制得叶绿素镁钠、脱镁叶绿素酸、铜叶绿素酸、叶绿素铜钠等一系列产品, 叶绿素的总收率为１－２３ ％ （ 以苎麻叶计） 。     

Electrochemical processes in the photoelectrolysis of nicotinamide adenine dinucleotide on the chlorophyll electrodes

The photoelectrolysis, in which redox compounds are electrolysed on a pair of photo-excitable electrodes by supplying photo—energy in place of electric energy, has been performed. The photo—excitable electrodes were prepared by coating a platinum plate with a thin layer of a chlorophyll—quinone composite. These electrodes were called chlorophyll electrodes. The chlorophyll electrode of chlorophyll—naphthoquinone composite worked as a cathode and that of chlorophyll—anthrahydroquinone composite as an anode when they were illuminated. The chlorophyll electrode of chlorophyll—naphthoquinone composite was characterized by an electrochemical behavior of p-type semiconductor electrode. Reduction of nicotinamide adenine dinucleotide (NAD⁺) was carried out on the chlorophyll electrode under illumination at various controlled electrode potentials. NAD was reduced at extremely noble electrode potentials are compared with the reductive potential of NAD⁺ to NADH. Electron transfer accompanied with the photoelectrochemical reactions is discussed.     

Blue Light Improves Photosynthetic Performance during Healing and Acclimatization of Grafted Watermelon Seedlings

To investigate the importance of light on healing and acclimatization, in the present study, grafted watermelon seedlings were exposed to darkness (D) or light, provided by blue (B), red (R), a mixture of R (68%) and B (RB), or white (W; 35% B, 49% intermediate spectra, 16% R) LEDs for 12 days. Survival ratio, root and shoot growth, soluble carbohydrate content, photosynthetic pigments content, and photosynthetic performance were evaluated. Seedling survival was not only strongly limited in D but the survived seedlings had an inferior shoot and root development, reduced chlorophyll content, and attenuated photosynthetic efficiency. RB-exposed seedlings had a less-developed root system. R-exposed seedlings showed leaf epinasty, and had the smallest leaf area, reduced chlorophyll content, and suppressed photosynthetic apparatus performance. The R-exposed seedlings contained the highest amount of soluble carbohydrate and together with D-exposed seedlings the lowest amount of chlorophyll in their scions. B-exposed seedlings showed the highest chlorophyll content and improved overall PSII photosynthetic functioning. W-exposed seedling had the largest leaf area, and closely resembled the photosynthetic properties of RB-exposed seedlings. We assume that, during healing of grafted seedlings monochromatic R light should be avoided. Instead, W and monochromatic B light may be willingly adopted due to their promoting effect on shoot, pigments content, and photosynthetic efficiency.     

藻类叶绿素a提取的优化研究

叶绿素a是参与光合作用的基础物质，是衡量水体藻类生物量以及评价湖泊富营养化的重要指标之一。利用90%丙酮、无水乙醇、无水乙醇∶90%丙酮（1∶1）、无水乙醇∶90%丙酮（1∶2）、无水乙醇∶90%丙酮（2∶1）五种有机溶剂萃取已知浓度标准叶绿素a和叶绿素b，对传统萃取叶绿素a的计算公式加以修正，并且在超声辅助破碎藻细胞的前提下分析了该五种有机溶剂对普通小球藻和铜绿微囊藻中叶绿素a的萃取效果。确定了无水乙醇∶90%丙酮（2∶1）的萃取效果最好，而无水乙醇从效果、安全、环保等角度考虑为最优溶剂。通过多参数水质监测仪对不同时间段的浅水型湖库水体中的叶绿素a进行监测，验证了在超声条件下无水乙醇测定结果的准确性并利用正交实验确定出了无水乙醇萃取叶绿素a的最佳条件。对于叶绿素a测定的优化研究使得以后野外水体大量测量叶绿素a的过程变得更为简便、快捷、准确。