克氏原螯虾中甲壳素提取工艺的优化

克氏原螯虾甲壳中的甲壳素含量较丰富,而针对克氏原螯虾中甲壳素的提取目前还没有公认的最优方法。本研究对比了EDTA法与生物发酵法提取甲壳素的效果,旨在找到提取此类虾中甲壳素的较优方法,以期为提高虾的利用率,减少虾加工产业中的资源浪费和防止环境污染提供理论依据。     

红螯螯虾壳制备壳聚糖的研究

以红螯螯虾壳为原料提取甲壳素,得到白色片状产品,收率为18%。甲壳素通过脱乙酰化制备壳聚糖,脱乙酰度可达83%。考察了浸酸时间、浸酸温度和NaOH浓度对产品质量的影响。结果表明,采用红螯螯虾壳制备壳聚糖是可行的。     

稻田常用6种化学农药对克氏原螯虾的安全性评价

[目的]研究6种化学农药对克氏原螯虾的毒性,评价其在稻虾生态种养田使用的安全性,为稻虾生态种养田化学农药的选择和正确使用提供科学指导。[方法]实验室采用室内半静态法测定了6种水稻田常用化学农药对克氏原螯虾24、48、72、96 h的毒性,应用概率单位法计算LC50、Turubell法计算安全质量浓度。[结果]200 g/L氯虫苯甲酰胺SC、10%三氟苯嘧啶SC、20%呋虫胺SG、75%三环唑WP、50%丁草胺EC和55%吡嘧·丙草胺WP对克氏原螯虾96 h LC₅₀分别为335.64、67.30、28.29、751.13、103.79、145.58 mg/L,6种化学农药对克氏原螯虾均为低毒;10%三氟苯嘧啶SC、20%呋虫胺SG、50%丁草胺EC和55%吡嘧·丙草胺WP对克氏原螯虾的安全质量浓度分别为21.41、5.40、1.71、9.60 mg/L,田间安全使用剂量分别为4281.64～6422.45、1079.99～1619.99、342.33～513.49、1919.38～2879.07 g a.i./hm2。[结论]6种化学农药均对克氏原螯虾低毒,在稻虾...     

微波消解-电感耦合等离子体质谱法测定克氏螯虾中10种重金属元素

克氏螯虾水产品是大众喜爱的常见餐桌食品,但产品内重金属元素含量较高。本文建立了一种采用微波消解-电感耦合等离子体质谱法(ICP-MS)的分析方法。该方法可同时测定克氏螯虾中镉、硒、铬、汞、铅等10种重金属元素含量。在经处理的克氏螯虾样品中加入过氧化氢-硝酸混合溶液,采用微波按全程序升温的方式进行消解,所得的无色透明样品溶液以锗、铟、铋为内标元素,供ICP-MS分析。待测元素的质量浓度在一定范围内标准曲线线性良好,相关系数r大于0.999。检出限(3SD)在0.0001～0.0006μg·L^-1之间,所分析的实际样品回收率在89.5%～105.0%之间,测试精度在0.15%～6.25%(RSD,n=6)。该方法快捷、方便、高效,适用检测水产品克氏螯虾中重金属元素的含量。     

微晶型甲壳素和壳聚糖的制备研究

本文叙述了低分子量微晶型多孔甲壳素和壳聚糖的制备,并对工艺条件进行了讨论。     

甲壳素衍生物的制备工艺

介绍了多种甲壳素衍生物的制备工艺和生产方法 ,包括壳聚糖、羧甲基甲壳素、羧甲基壳聚糖、乙酰化壳聚糖、羧丙 (乙 )基壳聚糖、微晶甲壳素及壳聚糖、盐酸氨基葡萄糖、甲壳素硫酸盐、溴化甲壳素、N-乙基壳聚糖、季铵化壳聚糖、壳聚糖接枝共聚产物等十多种。     

从虾蟹壳制备甲壳素及壳聚糖的研究

本文以云南出产的蟹、虾的外壳为原料,制备出粘度高、色泽洁白的甲壳素和壳聚糖产品。同时,对制备过程中酸、碱的浓度、反应温度和时间,配料比以及氧化还原的条件等对产品质量和收率的影响进行了研究。找出了较好的生产工艺条件。     

甲壳素的制备及二次开发

本文概述了甲壳素国内外研究的现状和发展趋势,目前制备方法改进的探讨,以及二次开发的方向和前景。     

甲壳素及壳聚糖的应用

介绍了甲壳素及壳聚糖的性质,概述了近年来甲壳素及壳聚糖在生物工程、化工环保、生物医学、食品工业等领域的应用进展。     

甲壳素改性产品的提取制备工艺的研究

甲壳素等相关改性产品作为目前发展迅速的新型材料，有着及其广泛的应用。本文主要对甲壳素的提取制备工艺及改性产品生产的优化条件进行了试验及分析研究，得出了具有较高经济效益的生产方法。     

甲壳素铁卟啉和壳聚糖铁卟啉催化性能差异研究

用紫外和红外光谱技术考察了含氮生物高分子甲壳素和壳聚糖对四苯基铁卟啉的固载差异性,并研究了这种差异对四苯基铁卟啉催化空气氧化环己烷反应的影响。实验结果表明,壳聚糖比甲壳素通过分子间力对四苯基铁卟啉有更强的吸附固载能力,它们对四苯基铁卟啉的吸附平衡常数分别为9.68×104和6.80×104L/mol。这种吸附能力差异引起所固载的铁卟啉催化空气氧化环己烷的性能差别。在相同的催化反应条件下,载体对铁卟啉吸附能力越强的催化剂催化环己烷氧化生成酮和醇的速率越快,获得越高的产物选择性和催化剂转化数。     

Current state of chitin purification and chitosan production from insects

Chitin, and especially its deacetylated variant chitosan, has many applications, e.g. as carrier material for pharmaceutical drugs or as a flocculant in wastewater treatment. Despite its versatility and accessibility, chitin, the second most abundant polysaccharide on Earth, has so far been commercially extracted only from crustaceans and to a minor extent from fungi. Insects are a viable alternative source of chitin, but they have not been exploited in the past due to limited availability. Today however, for the sustainable production of animal feed, insect farming is being developed substantially. The availability of large quantities of insect biomass and chitin-rich side products such as exuviae and exoskeletons has been increasing. This review provides an overview of recently published studies of chitin extraction from insects, its subsequent conversion into chitosan and the primary analytical methods used to characterize insect-based chitin and chitosan. We have discovered a large number of research articles published over the past 20 years, confirming the increased attention being received by chitin and chitosan production from insects. Despite numerous publications, we identified several knowledge gaps, such as a lack of data concerning chitin purification degree and chitosan yield. Furthermore, analytical methods used to obtain physicochemical characteristics, structural information and chemical composition meet basic qualitative requirements but do not satisfy the need for a more quantitative evaluation. Despite the current shortcomings that need to be overcome, this review presents encouraging data on the use of insects as an alternative source of chitin and chitosan in the future. © 2020 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).     

Adsorption of aluminium from wastewater by chitin and chitosan produced from silkworm chrysalides

Chitin, extracted from silkworm chrysalides, was employed for the production of a high‐purity and porous chitosan, as observed by scanning electron microscopy. Chitin and the chitosan produced from it were also analysed using ¹³C NMR spectroscopy to show the efficiency of deacetylation. The extracted chitin was investigated as an adsorbent material for aluminium removal from textile wastewater, by the column chromatographic method. After the treatment, the residual aluminium was lower than the limitation criterion of 0.2 mg L^?1. The isotherms of adsorption on chitin and chitosan surfaces were investigated and the best fits were observed using the Freundlich isotherm. At pH 5.0, the maximum adsorption capacity was 21.3 mg of aluminium per gram of chitosan over 70 h of experiments. Copyright © 2006 Society of Chemical Industry     

酶载体壳聚糖制备的研究

本文分别采用电热法、连续微波法和问歇微波法制备了几种性能不同的壳聚糖,并对产品的脱乙酰度和分子量进行了比较.结果表明,间歇微波法制备的壳聚糖具有制备时间短、产品脱乙酰度高和分子量大等特点,能更好地满足酶载体的要求.     

Chitin and chitosan nanofibers: electrospinning of chitin and deacetylation of chitin nanofibers

An electrospinning method was used to fabricate chitin nanofibous matrix for wound dressings. Chitin was depolymerized by gamma irradiation to improve its solubility. The electrospinning of chitin was performed with 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as a spinning solvent. Morphology of as-spun and deacetylated chitin (chitosan) nanofibers was investigated by scanning electron microscopy. Although as-spun chitin nanofibers had the broad fiber diameter distribution, most of the fiber diameters are less than 100 nm. From the image analysis, they had an average diameter of 110 nm and their diameters ranged from 40 to 640 nm. For deacetylation, as-spun chitin nanofibous matrix was chemically treated with a 40% aqueous NaOH solution at 60 or 100 °C. With the deacetylation for 150 min at 100 °C or for 1day at 60 °C, chitin matrix was transformed into chitosan matrix with degree of deacetylation (DD) ∼85% without dimensional change (shrinkage). This structural transformation from chitin to chitosan was confirmed by FT-IR and WAXD.     

水溶性固体壳聚糖盐的制备及其性能研究

通过半湿研磨法由壳聚糖制备了多种水溶性粉末状壳聚糖盐。该产品可以溶解在酸性、中性和弱碱性介质中,溶解范围扩大;水溶液pH值在3.36—5.54之间,而且具有较强的缓冲作用;吸湿率提高30%以上。通过红外光谱、X-射线衍射、质量损失曲线及电位滴定曲线对目标产物结构进行分析,结果表明,在无溶剂条件下实现了壳聚糖氨基的质子化反应而不是简单的物理吸附,因此产品性能稳定。该方法操作简单,无污染而且经济。     

甲壳素制备壳聚糖脱乙酰度可控性的研究

介绍了甲壳素（ehintin）和壳聚糖（ehitosan）的性质、用途及发展前景;分析了国内外对壳聚糖的研究状况及取得的成果;描述了制备壳聚糖的实验原理;初步研究了在保证能获得大分子量的情况下提高壳聚糖的脱乙酰度的实验方法;介绍了测定壳聚糖脱乙酰基的实验方法;分析了影响壳聚糖脱乙酰度（Degree　of　 Deacetylation缩写：D．D．）的主要因素。