应用刚果红-壳聚糖褪色反应光度法测定微量阳离子表面活性剂

在pH 10.5的B-R(或pH 9.0的氨水-氯化铵)缓冲溶液中,溴化十六烷基三甲胺和氯化十六烷基吡啶能使刚果红与壳聚糖(体系Ⅰ)或刚果红与羧甲基壳聚糖(体系Ⅱ)生成的有色物质产生灵敏的褪色反应,在530 nm波长处,其褪色程度△A与溴化十六烷基三甲胺及氯化十六烷基吡啶用量呈线性关系,溴化十六烷基三甲胺和氯化十六烷基吡啶的质量浓度分别在0.2～3.6 mg·L-1(体系Ⅰ)和0.08～3.2 mg·L-1(体系Ⅱ)范围内呈线性,表观摩尔吸光率εCTMAB=2.08×104L·mol-1·cm-1,εCPC=2.52×104L·mol-1·cm-1(体系Ⅰ);εCTMAB=2.22×104L·mol-1·cm-1,εCPC=2.55×104L·mol-1·cm-1(体系Ⅱ),拟定的方法用于水样中微量阳离子表面活性剂的测定,测得方法的回收率在99.1%～100.8%之间,测定值的相对标准偏差(n=6)在1.2%～3.0%之间.     

保健食品中壳聚糖含量检测新方法的研究

在pH 5.5的B-R(Britton-Robinson)缓冲溶液中壳聚糖对荧光素的吸光度度具有明显的降低作用,且降低程度与加入的壳聚糖浓度成线性关系,据此建立了一种新的测定壳聚糖含量的分光光度法。该方法线性回归方程为A=0.36414-0.04854C,线性范围为15~150 mg/L,相关系数R为0.9911,检出限为9.36 mg/L,平均回收率为99.6%,用荧光光度法做了对照实验,结果一致。采用该方法可测定复杂样品中微量壳聚糖的含量。     

顶空气相色谱法测定羧甲基壳聚糖中氯乙酸残留量

采用顶空气相色谱法间接测定了羧甲基壳聚糖中氯乙酸的残留量。样品(0.2g)于顶空瓶中超声溶解在水3mL中,加入甲醇2.5mL,硫酸1.5mL,在70℃水浴反应40min使之酯化。按顶空条件进样,用HP-INNOWAX毛细管色谱柱分离,氢火焰离子化检测器测定。分别选择15min和85℃作为样品在顶空瓶中的平衡时间和平衡温度。氯乙酸的质量在0.2～20mg范围内与其峰面积呈线性关系,方法的检出限(3S/N)为5.6mg·L-1。方法用于实样中氯乙酸的测定,用标准加入法做回收试验,测得回收率在90.0%～92.0%之间,测定值的相对标准偏差(n=5)在0.7%～0.9%之间。     

交联羧甲基壳聚糖吸附痕量汞研究

研究了交联羧甲基壳聚糖对Hg2 的吸附作用,探讨了溶液的pH值、反应时间、温度、样品体积、共存组分等因素对其吸附性能的影响.实验表明,在pH=5时,羧甲基壳聚糖对Hg2 的吸附性能很好,吸附率可迭95%以上,并且具有良好的重复使用性能,其吸附行为满足Langmuir等温式,饱和吸附容量为125.1mg/g,方法的相对标准偏差为7.8%.用于分析实际水样时,回收率达96～以上.     

芦丁在酸碱溶液中的紫外光谱研究与应用

芦丁在酸碱溶液中具有不同的紫外吸收光谱.以芦丁的碱性溶液(pH 9.25)为测定液,以等浓度的芦丁酸溶液(pH 2.0)为参比液,用差示法测量其吸光度.结果表明:在405 nm处,当芦丁质量浓度为2.5～25 μg/mL时,吸光度与质量浓度之间存在良好的线性关系,据此建立了差示紫外吸收光度法.并用此法直接测定了芦丁片和槐米中的芦丁,回收率分别为98.8%～102.7%(RSD=1.1%)、97.0%～105.5%(RSD=2.1%).     

光度法测定新疆阿魏中多糖的含量

采用苯酚-硫酸光度法对新疆阿魏中多糖含量进行了测定.测定波长485nm,多糖换算因子f=3.179,在10.0～70.0 mg·L-1范围内吸光度与被测物含量呈线性关系,方法的回收率在98.6%～102.2%之间.方法的相对标准偏差(n=5)为0.20%.     

天然高分子电场敏感水凝胶——大豆蛋白/羧甲基壳聚糖体系

通过将大豆蛋白(SPI)和羧甲基壳聚糖(CMCS)进行溶液共混,并加入环氧氯丙烷作为交联剂,成功制备了一种天然高分子两性荷电水凝胶.这种SPI/CMCS水凝胶在电场的作用下可以快速弯向一侧电极,表现出很好的电场敏感性.由于该水凝胶具有两性荷电的特性,因此其在不同pH值的电解质溶液中既可以弯向阳极(当pH6时),也可以弯向阴极(当pH6时).除了pH的变化,其他诸如施加电压的大小以及水凝胶的厚度也会对SPI/CMCS水凝胶在电场中的行为产生影响.相比于先前报道的另外两种天然高分子电场敏感水凝胶,即壳聚糖/羧甲基纤维素水凝胶和壳聚糖/羧甲基壳聚糖水凝胶,SPI/CMCS水凝胶在酸性较强(pH=3～4)以及中性(pH=7)的环境中仍能表现出良好的电场敏感性,拓展了天然高分子电场敏感水凝胶的应用范围.     

胶原-磺化羧甲基壳聚糖/硅橡胶皮肤再生材料的制备及其对小型猪烫伤创面全层皮肤缺损的修复研究

制备了一种胶原-磺化羧甲基壳聚糖/硅橡胶皮肤再生材料,并以小型猪为模型,考察了其对烫伤全层皮肤缺损的修复性能.首先合成了磺化羧甲基壳聚糖,并对其结构进行了表征.制备了胶原-磺化羧甲基壳聚糖多孔支架,采用扫描电子显微镜(SEM)研究了磺化羧甲基壳聚糖含量对支架微结构的影响.随着磺化羧甲基壳聚糖含量的增大,胶原-磺化羧甲基壳聚糖支架从纤维结构向片状结构转化,且支架的孔径相对变大.采用体外成纤维细胞培养实验证明胶原-磺化羧甲基壳聚糖支架无明显细胞毒性.进一步将胶原-磺化羧甲基壳聚糖支架与硅橡胶膜复合,构建具有双层结构的皮肤再生材料.以小型猪为模型,评价了其对深度烫伤创面的修复性能.大体观察和组织学分析结果显示,胶原-磺化羧甲基壳聚糖/硅橡胶皮肤再生材料具有更快的血管化性能,且经该材料处理的创面能有效支持薄自体皮片的移植成活,实现深度烫伤创面的全层修复.     

羧甲基壳聚糖修饰的开管毛细管电色谱柱的制备与表征

以γ-(2,3-环氧丙氧基)丙基三甲氧基硅烷为偶联剂,将羧甲基壳聚糖键合至毛细管内壁上。对毛细管预处理、硅烷化以及羧甲基壳聚糖键合反应参数进行了优化,考察了开管柱内表面结构形貌、电渗流、重现性和电色谱分离性能。扫描电镜图显示羧甲基壳聚糖均匀地键合在毛细管内表面。调节流动相的pH值可产生正向和反向电渗流,电渗流的相对标准偏差(RSD): 日内小于0.8%(n=6)、日间小于3.5%(n=3)、同一批次间小于4.3%(n=3)、不同批次柱间小于6.1%(n=3),重现性较好。4种核苷酸(腺嘌呤核苷酸、鸟嘌呤核苷酸、胞嘧啶核苷酸、尿嘧啶核苷酸)在修饰后的毛细管电色谱柱上得到了较好的分离,柱效达到36000～182000 塔板/m。结果表明,所建立的开管柱制备方法简单有效、稳定性好。     

钒酸铵氧化-分光光度法测定盐酸氯丙嗪

在磷酸介质中,钒酸铵与盐酸氯丙嗪反应生成红色氧化产物,其最大吸收波长为524nm;据此建立了测定盐酸氯丙嗪含量的钒酸铵氧化-分光光度法,并将其用于直接测定药物制剂中的盐酸氯丙嗪.结果表明,当盐酸氯丙嗪的浓度处于10.0～100mg/L和100～360mg/L范围内时,被测定体系的吸光度与盐酸氯丙嗪的浓度之间呈良好的线性关系;线性回归方程分别为A=-0.061 69+0.010 05c(mg/L,r=0.998 8)、A=0.494+0.004 43c(mg/L,r=0.998 8),检出限为1.96mg/L,相对标准偏差为0.29%,回收率为94.9%～102.9%.     

电荷注入检测器电感耦合等离子体光谱仪测定非金属元素的分析性能

研究了电荷注入检测器ICP光谱仪测定非金属元素的分析性能。以S、P、As、Se为代表的非金属元素在170－800nm波段内最灵敏的谱线均处于175－200nm远紫外区内。在此区内等离子体有很低的光谱背景发射和良好的谱线测量和背景测量的光度精度。标准曲线线性动态范围在4个数量级。给出了As,Se,S,P主要分析线的灵敏度、线背比、背景等效浓度及检出限。在纯水溶液中的检出限分别为：As 189.142nm 0.003mg/L,P213.618nm 0.005mg/L,S 180.731nm 0.01mg/L,Se 196.090nm 0.009mg/L.     

Production of ginseng saponin and polysaccharide by cell cultures ofPanax notoginseng andPanax ginseng

The effects of various combinations of the two kinds of phytohormones, auxin and cytokinin, on cell growth and production of ginseng saponin and polysaccharide were investigated in suspension cultures ofPanax notoginseng. It was found that a high concentration of kinetin (KT) (7 mg/L) seriously inhibited cell growth, but that of benzyl adenine (BA) did not. Under 0.7 mg/L of cytokinin (i.e., KT and BA), 2,4-dichlorophenoxy acetic acid (2,4-D) at 0.2 mg/L was better for the cell cultures than that at 2 or 20 mg/L; and for both naphthalene acetic acid (NAA) and indole acetic acid (IAA), 20 mg/L was their best level for the cell cultures. The highest cell concentration of 11.9 g/L (by dry wt) was obtained with the combination of 0.2 mg/L of 2,4-D and 0.7 mg/L of BA. The highest saponin content of 13.9% was achieved under 2.0 mg/L IAA and 0.07 mg/L KT; its highest production, i.e., 1.13 g/L, was obtained at 0.2 mg/L of 2,4-D and 0.7 mg/L of KT. Under 20 mg/L NAA and 0.7 mg/L KT, the highest polysaccharide content and production were reached, i.e., 16.4% and 1.86 g/L, respectively. In this work, the effects of phytohormones onP. ginseng cell cultures were also studied. A high saponin production of 1.78 g/L was observed at 10 mg/L of indole butyric acid and 0.1 mg/L of BA, and the highest production of polysaccharide (1.95 g/L) was reached with the combination of 10 mg/L NAA and 0.1 mg/L KT.     

电荷注入检测器电感耦合等离子体光谱仪测定铂族元素的性能

研究了用电荷注入检测器等离子体光谱仪测定铂族元素的分析性能。结果表明铂族元素有较好的检出限和10^4以上的线性动态范围，铂族元素间光谱干扰很少，在元素浓度＞1mg/L时测量精度可优于1％，钠对铂族元素的影响是轻微的。     

电感耦合等离子体发射光谱(ICP-OES)法测定传统发酵白酸汤中矿物质元素及主要营养成分分析

为探究传统发酵白酸汤中对人体有益的矿物质元素及营养成分,通过试验确定了ICP-OES测定传统白酸汤中矿物质含量的方法,并对主要营养成分进行了测定分析。结果表明,使用10%浓硝酸梯度升温消解传统白酸汤样品效果最好,测定方法相对标准偏差RSD为 0.26%～2.35%,平均加标回收率范围在 96.5%～113.6%,说明使用ICP-OES法测定白酸汤中矿物质元素具有较高准确度及精密度。样品中4种常量元素钙、镁含量丰富为51.4308mg/L、37.7304mg/L,钠、钾元素含量分别为6.6631mg/L 、1.6452mg/L;5种微量元素铜、锌、铁、锰及硅含量在0.0516mg/L～2.4851mg/L,铝元素未检测到。功能性成分多酚含量为11.844±0.051mg/L,蛋白质含量为6.392±0.021g/L,氨基酸含量为2.767±0.04mg/L,有害物质亚硝酸盐在安全标准下含量为0.601mg/L。该结果为白酸汤的研究及相关产品的开发提供了理论基础。     

电感耦合等离子体光谱法(ICP-AES)测定银精矿中铜、铅、锌、砷、镉、钙、镁、锰含量

针对银精矿样品复杂,难消解的特点,研究了不同酸溶法和碱熔法对样品的消解情况,建立了硝酸,盐酸,氢氟酸,高氯酸消解银精矿的方法。根据元素灵敏度和抗干扰性,选定各元素的测定波长。通过酸溶样和碱熔样测定结果比对,验证了方法准确性。建立了四酸消解-电感耦合等离子体光谱法测定银精矿中铜、铅、锌、砷、镉、钙、镁、锰含量的方法,元素的线性相关系数均在0.9999以上。通过共存元素干扰实验,确定了银精矿中高含量元素(铜、铅、锌、铁、锑、铋等)对测定元素结果没有影响。方法检出限：Cu 0.0063 mg/L, Pb 0.0159 mg/L ,Zn 0.0090 mg/L,As 0.0192 mg/L, Cd 0.0093 mg/L ,Ca 0.0084 mg/L, Mg 0.0075 mg/L, Mn 0.0081 mg/L。测定下限：Cu 0.0105mg/L,Pb 0.0265 mg/L, Zn 0.0150 mg/L, As 0.0320 mg/L, Cd 0.0155 mg/L, Ca 0.0140 mg/L, Mg 0.0125 mg/L,Mn 0.0135 mg/L。3个样品的相对标准偏差在0.87%~3.56%之间,加标回收率在95.00%~103.56%之间。方法流程短,操作简单,快速,灵敏度和再现性高,结果准确可靠,可以满足银精矿中铜、铅、锌、砷、镉、钙、镁、锰含量的测定。     

Two-dimensional electrophoresis of Cereus peruvianus (Cactaceae) callus tissue proteins

Two-dimensional electrophoresis of Cereus peruvianus callus tissues grown in culture media containing two different 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin combinations was used to identify minor differences in polypeptide composition of these cell clones. Altered expression during growth in the two 2,4-D and kinetin combinations was apparent for 13 polypeptides when calluses in the two media were compared. The number of proteins with differential expression (presence or absence of specific spots) was higher in callus tissues cultured in the 4.0 mg/L 2,4-D and 8.0 mg/L kinetin combination than in callus tissues cultured in the 4.0 mg/L 2,4-D and 4.0 mg/L kinetin combination. The present results show that the callus tissues maintained at 4.0 mg/L 2,4-D and 8.0 mg/L kinetin can be used as a matrix for in vitro selection programs.     

Anaerobic-anoxic-aerobic sequential degradation of synthetic wastewaters

This study was conducted in a continuous three-stage system of anaerobic (R1)-anoxic(R2)-aerobic (R3) reactors with synthetic wastewater containing phenol (1000 mg/L), chemical oxygen demand (COD) (3000 mg/L), CN⁻ (30 mg/L), SCN⁻(400 mg/L), and NH ₄ ⁺ -N (600 mg/L) as principal pollutants and well-acclimated heterogeneous microbial cultures. The final effluent was partially returned to R2 with a recycle ratio of 1. Anaerobic stage served to detoxify the feed by removing up to 80% of cyanide. Complete SCN⁻ removal and denitrification could be achieved in the anoxic stage by utilizing phenol as an internal source of carbon. Nitrification efficiency of 93% was obtained in the aerobic reactor. The results demonstrated that the three-stage system can give the desired final treated effluent quality (0 mg/L of phenol, 0.2 mg/L of CN⁻, 210 mg/L of COD, and 20 mg/L of NH ₄ ⁺ -N) and that the NO ₃ ⁻ -N concentration can be lowered by a higher recycle ratio.     

Removal of strontium from an aqueous solution using co-precipitation followed by microfiltration (CPMF)

This study characterized the removal of strontium from an aqueous solution via co-precipitation followed by microfiltration (CPMF) on a lab-scale. Sodium carbonate was used as the precipitating agent. Ferric chloride was added to a settler at a dosage of 20 mg/L to improve strontium removal, and it was added to a membrane separator at a dosage of 10 mg/L to reduce membrane fouling. The concentration of strontium in the raw water used in this study was about 5 mg/L. In two intermittent tests, where dosages of sodium carbonate were 2000 mg/L and 1000 mg/L, the mean decontamination factors (DFs) were 237 and 158 and the mean concentration factors (CFs) were 288 and 462, respectively. Although the mean DF value was lower when the sodium carbonate dosage was 1000 mg/L instead of 2000 mg/L, the rate at which the specific flux (SF) of the membrane declined decreased as the amount of the effluent treated increased. The problem of strontium release at the beginning of the operation was controlled by a continuous test in which the dosage of sodium carbonate still was 1000 mg/L and the other parameters were the same as in the other tests. The results showed that the mean DF and CF were 157 and 480, respectively.     

2,3,5,4'- tetrahydroxystilbene-2-O-β-D-glycoside biosynthesis by suspension cells cultures of Polygonum multiflorum Thunb and production enhancement by methyl jasmonate and salicylic acid

Friable calli of Polygonum multiflorum Thunb have been induced in MS medium supplemented with 6-benzylaminopurine (6-BA) and kinetin (KT). Suspension cultures were initiated from friable calli by inoculating calli in liquid MS medium in shake flasks in the dark and 25 °C on an orbital shaker at 100 rpm. The maximum dry weight (DW, 7.85 g/L) and 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glycoside (THSG, 56.39 mg/L) of suspension cells was obtained in MS medium after 16 days culture. Both methyl jasmonate (MeJA) and salicylic acid (SA) could increase THSG production. The most appropriate concentration of MeJA was 100 μmol/L in MS medium, in which concentration THSG content reached the maximum value of 147.79 mg/L, which represented a 162.36% increase compared to that of the control (56.33 mg/L). The most appropriate concentration of SA was 125 μmol/L in MS medium, at which concentration THSG content reached its maximum value of 116.43 mg/L, a 106.69% increase compared to that of the control (56.33 mg/L).     

差分脉冲溶出伏安法测定陶瓷器皿中铅和镉的溶出率

采用4%的乙酸浸泡陶瓷样品24 h,应用同位镀汞差分脉冲溶出伏安法测定了陶瓷样品中微量重金属铅、镉的溶出量。以0.1 mol/L的硝酸溶液做底液,0.1 mol/L的KCl溶液做支持电解质,2 g/L的Hg2+溶液做镀汞液,测得铅的溶出峰电位为-0.5 V(vsSCE),镉的溶出峰电位为-0.7 V(vsSCE),两者含量在5×10-4～1 mg/L和5×10-4～0.5 mg/L范围内峰电流和其含量呈良好的线性关系,检出限分别为2×10-4和4.3×10-3mg/L。