ICP-AES检测云南稻核心种质矿质元素含量的地带性特征

采用电感耦合等离子体原子发射光谱法(ICP-AES)测定了云南省5个稻作区16个州市的789份地方水稻糙米中的八种矿质元素,该方法简单快速、灵敏度高、准确性好和多元素同时测定,加标回收率为97.1%～110.2%,RSD为0.7%～4.4%.结果表明:糙米元素含最(mg·kg-1)依次为P(3834.83±486.49)＞K(2567.72±336.74)＞Mg(2567.72±336.74)＞Ca(153.67±55.90)＞Zn(33.35±13.65)＞Fe(32.08±25.51)＞Cu(14.22±11.85)＞Mn(13.58±3.22);世界生物多样性最丰富及有色金属富集的滇西北糙米P含量高,早寒武纪动物群及磷矿富集的滇中糙米Ca,Mg,Fe和Zn含量高,作物多样性突出的滇西南糙米Cu和Mn含量高;糙米高磷钾、中钙镁锰和低铁锌分布区是世界生物多样性最丰富及矿产资源富集区.首次提出云南糙米矿质元素含量的地带性特征与生物多样性中心、矿产资源寓集区、生命起源及其山脉、河流有关;进一步推断地球矿质元素分布不均匀性及其山脉、河流的相互作用是生命起源的关键.文章研究为解决人类Fe,Zn和Ca等矿质营养不良和生命起源问题以及功能稻米育种生产提供参考.     

水田污染区稻壳与糙米中铬元素的LIBS分析可行性

为验证激光诱导击穿光谱(LIBS)对江西省环鄱阳湖水田污染区稻谷中铬元素的分析可行性,本试验以在该区收集的稻壳、糙米和白米作为研究对象,分别对所有样品进行LIBS测试,并利用火焰原子吸收法(AAS)对铬元素进行真实浓度检测。LIBS图谱显示稻壳中明显地检测到了铬元素的特征谱线,而糙米和白米则检测不到。AAS结果显示稻壳中Cr浓度远高于糙米,而白米中Cr未超标,同时,稻壳与糙米Cr浓度比率具有一定的梯度关系。结果说明,Cr在稻壳中的富集量高于糙米和白米,利用LIBS技术对稻壳中Cr进行检测具有一定的可行性,最终有望实现通过采集稻壳LIBS光谱信号,预测出糙米中重金属元素的分布规律,进而采用类似的方法获取大米中重金属元素含量。     

不同成熟度双孢菇子实体主要营养元素与矿物质的光谱分析

采用电感耦合等离子体-原子发射光谱(ICP-AES)法对小菇到开伞的4个不同成熟度(Ⅰ,Ⅱ,Ⅲ,Ⅳ)双孢菇子实体的Na,K,P,Ca,Mg等常量元素及Cu,Se,Mo,Fe等微量元素含量进行了测定,同时对水分含量、可溶性蛋白、可溶性糖、维生素C等含量进行了分析。结果发现成熟度Ⅰ的双孢菇子实体中Na,K,P,Mg,Cu,Se,Mo含量均显著高于其他3个成熟度(α=0.05),Ca和Fe的含量均显著高于成熟度Ⅲ和Ⅳ;成熟度Ⅳ的Se含量显著高于成熟度Ⅱ和Ⅲ,Na含量显著高于成熟度Ⅱ,Cu含量显著高于成熟度Ⅲ;成熟度Ⅱ和Ⅲ的K,P,Ca,Mg,Mo,Fe的含量显著高于成熟度Ⅳ;而成熟度Ⅳ的含水量显著高于成熟度Ⅰ和Ⅲ,与成熟度Ⅱ的无显著性差异;4个成熟度的可溶性蛋白含量均无显著差异;成熟度Ⅳ的可溶性糖含量显著低于其他3个成熟度;成熟度Ⅲ的维生素C含量与成熟度Ⅰ的无显著性差异,但显著高于成熟度Ⅱ和Ⅳ,成熟度Ⅰ与Ⅳ的维生素C含量显著高于成熟度Ⅱ。通过对4个成熟度双孢菇子实体矿质元素和营养成分含量的分析,发现成熟度Ⅰ和Ⅱ的双孢菇子实体是人体必需的矿物质元素更优质的来源,但总的来说成熟度不同的双孢菇(过大和过小的)仍然可以作为优质鲜食菇品出售,为食品加工企业和消费者选择双孢菇产品提供有利依据。     

半导体异质结(111)面的界面偶极子及其对能带偏移的影响

本文采用紧束缚的界面键极性模型(interface-bond-polarity-model),计算了匹配的半导体异质结(111)面的界面偶极子,并将计算结果与(110)和(001)面的结果进行了比较,讨论了界面取向和界面成分对偶极子的影响。结果表明,对于两边同是Ⅲ-V族半导体或同是Ⅱ-Ⅵ族半导体的异质结,界面偶极子几乎不依赖于界面的取向和界面的组成,因此,能带偏移也基本上是各向同性的。对于两边由不同类型半导体组成的异质结,如Ⅱ-Ⅵ/Ⅲ-Ⅴ体系、Ⅲ-Ⅴ/Ⅳ和Ⅱ-Ⅵ/Ⅳ体系,混和的阴离子(111)界面给出的偶极子小于零,而混和的阳离子(111)界面给出的偶极子大于零,二者的平均值等于中性的(110)界面的偶极子。 关键词：     

氢化物发生-原子荧光光谱法直接测定土壤水溶态Sb(Ⅲ)和Sb(Ⅴ)

在HCl介质中,Sb(Ⅲ)和Sb(Ⅴ)在氢化物发生过程中的化学反应效率不同,通过测定经还原剂还原后和还原前Sb的荧光强度,求解联立方程计算出Sb(Ⅲ)和Sb(Ⅴ)的含量,据此建立了氧化物发生-原子荧光光谱法直接测定土壤水溶态Sb(Ⅲ)和Sb(Ⅴ)方法,操作简便,实用性强.考察了 HCl浓度和KBH_4浓度对Sb(Ⅲ)和Sb(Ⅴ)测定灵敏度的影响以及共存元素的干扰情况,并比较了丽种还原剂对Sb(Ⅴ)的还原效果.方法检出限为Sb(Ⅲ)1.11 ng·g~(-1),Sb(Ⅴ)1.57 ng·g~(-1).加标回收试验表明方法准确、可靠.     

兴凯湖沉积物富里酸荧光特性研究

采集黑龙江省兴凯湖4个点位沉积物样品(样品号HXXD,HXXX,HXDX,HXDB),开展了沉积物富里酸(fulvic acid, FA)荧光特性研究。二维荧光光谱、三维荧光光谱均显示HXXD点位FA的主要荧光峰均出现在较长波长处。FA荧光光谱特征参数分析表明,各点位富里酸腐殖化程度为：HXXD>HXDX>HXDB>HXXX。其中HXXD点位FA以陆源输入为主,而其他点位FA则陆源与水生生物源并存。利用荧光区域积分(FRI)技术,对FA的三维荧光光谱5个区域(Ⅰ-Ⅴ)的荧光响应值比例(percent fluorescence response, P_{i, n})比较证实,所有点位类胡敏酸区域(Ⅴ区)的P_{Ⅴ, n}、类富里酸(Ⅲ区)的P_{Ⅲ, n}均占有较大的比例,同时采用三维荧光区域积分法判断各点位FA腐殖化程度与二维荧光特性结论一致。三维荧光光谱中r_{(A, C)}值与区域积分(FRI)中P_{Ⅴ, n}/P_{Ⅲ, n}及(P_{Ⅴ, n}+P_{Ⅲ, n})/(P_{Ⅰ, n}+P_{Ⅱ, n}+P_{Ⅲ, n})均具有显著的相关性,因此,r_{(A, C)}值是兴凯湖沉积物FA腐殖程度表征的一个方便、快捷的参数。     

锑化铟的物理特性及其应用

一、引言锑化铟(InSb)是近年来引起人们极大兴趣并被广泛研究的Ⅲ-Ⅴ族化合物半导体材料。 InSb和锗(Ge)、硅(Si)相比虽是一发现较晚的半导体材料,但自从1952年惠耳克尔(Welker),首先对InSb进行研究之后,十年来对InSb各方面的性能及其应用已做了很多研究工作。这主要是因为:(1)制备高纯度InSb的工艺相对地比较简单,较容易获得其纯度比Ge、Si或其他Ⅲ-Ⅴ族半导性化合物高一、二个数量极的单晶体。(2)由于InSb具有一些显著的     

流动注射-多道检测-催化动力学同时测定铜和铁

基于Cu(Ⅱ),Fe(Ⅲ)在pH3～9范围内能同时催化过氧化氢氧化罗丹明B的褪色反应,探讨了最佳反应条件,通过构建流动注射pH梯度,采用CCD-二极管阵列检测器检测吸光度差值,反向传播-人工神经网络(BP-ANN)处理数据,实现了Cu(Ⅱ),Fe(Ⅲ)流动注射-催化动力学光度法的同时测定。Cu(Ⅱ)和Fe(Ⅲ)的检出限分别为0.10和0.21μg·L~(-1),采样频率为10次·h~(-1),本法用于标准参考物质和食品样品中铜、铁的同时测定,结果满意。     

Synthesis,Spectroscopic Characterization,Thermogravimetric and Biological Activity Evaluation of Te(Ⅳ),Se(Ⅳ),V(Ⅲ),Nb(Ⅴ),Ta(Ⅴ)Complexes With Indole-3-Acetic Acid Plant Hormone Ligand

Te(Ⅳ), Se(Ⅳ), V(Ⅲ), Nb(Ⅴ) and Ta(Ⅴ) complexes of indole-3-acetic acid (IAAH) ligand were synthesized, characterized by elemental analysis and various spectroscopic techniques like, IR, 1H-NMR, X-ray powder diffraction, UV-Visible, thermogravimetry analysis, magnetic measurements, molar conductance and surface morphology using SEM. All the synthesized complexes of IAAH ligand have 1∶2 stoichiometry of the types [Te(IAA)₂(NH₃)₂]·2Cl (Ⅰ), [Se(IAA)₂(NH₃)₂]·2Cl (Ⅱ), [V(IAA)₂(NH₃)(Cl)] (Ⅲ), [Nb(IAA)₂(Cl)₃] (Ⅳ), and [Ta(IAA)₂(Cl)₃] (Ⅴ). Spectral analysis indicates octahedral geometry for the Te(Ⅳ), Se(Ⅳ) and V(Ⅲ) complexes, whereas both Nb(Ⅴ) and Ta(Ⅴ) have a seven-coordination. The bonding sites are the oxygen atoms of carboxylate group for the deprotonated indole-3-acetic acid (IAA) ligand. The thermogravimetry analysis studies gave evidence for the presence of other coordinated molecules (Cl or NH₃) in the composition of IAA complexes, which were further supported by IR and micro analytical measurements. The higher molar conductance data of tellurium and selenium (Ⅳ) complexes reveal that these chelates are electrolytes, while low conductivity values for the vanadium(Ⅲ), niobium and tantalum(Ⅴ) chelates indicated a non-electrolytes. To test the antibacterial property of the five complexes in this study, four bacterial strains Klebsiella (G-), Escherichia coli (G-), Staphylococcus aureus (G+) and Staphylococcus epidermidis (G+) were used in the investigation. The effects of the five complexes in the cytotoxicity of Caco-2 and Mcf-7 human cancer cell lines were studied Neutral red uptake assay for the estimation of cell viability/cytotoxicity protocol.     

ICP-AES法测定粳稻近等基因系群体间糙米的矿质元素

采用电感耦合等离子体原子发射光谱法(ICP-AES)对粳稻近等基因系(NILs)BC5F5群体264个株系17种矿质元素(S,Mo,Ni,Fe,Cr,Na,Al,Cu,P,Sn,Zn,B,Mn,Mg,Ca,Sr,K)进行了测定。加标回收率为92.3%~110.2%,RSD<6%。结果表明:以丽粳2号作供体及十和田受体培育出糙米多种高矿质元素基因定位的NILs,是迄今首次培育出粳稻孕穗期耐冷性及其关联矿质元素的近等基因系;该群体糙米中P,K,Mg,S,Ca,Zn,Mn,Na,Fe,Cu和Al等11种人体必须的生命元素含量较高;群体间糙米矿质元素中五种宏量元素含量变异小(11.15%~16.45%)和12种微量元素变异大(16.57%~94.96%);群体糙米17种矿质元素间136对性状间有95对性状呈显著或极显著相关,而与功能稻米活性成分有关的Mo,Ni,Al,Sn,Cr和Sr矿质元素15对性状相关(0.531**~0.921**)明显高于P,K,Ca,Mg和S宏量元素10对性状相关(0.175**~0.867**)。研究结果为糙米矿质元素的基因定位克隆提供了有益的参考数据。     

The promoted hydrolysis effect of cellulase with ultrasound treatment is reflected on the sonicated rather than native brown rice

Brown rice is nutritionally superior to polished white rice, as it maintains a large content of external bran that involves a series of bioactive compounds. However, the presence of bran also restricts water diffusion and results in adverse quality of brown rice. In this work, ultrasound conditions were optimized for cellulase to improve its hydrolysis effect on rice bran, and combinations of enzymatic and ultrasound treatment in different manners were conducted on brown rice, to improve the textural attributes. The results showed significant improvements in the catalytic activity and efficiency of cellulase after ultrasonication at the optimal intensity of 1.67 W cm⁻³ and duration of 30 min, with the conformational variation of cellulase observed from the fluorescence spectra and circular dichroism (CD). Despite the enhanced activity of ultrasonicated cellulase, it leaded to a similar rice surface morphology and a comparable amount of released glucose, and equivalent textural parameters of brown rice treated by native cellulase. However, for the pre-sonicated brown rice, the ultrasonicated cellulase showed a significantly higher hydrolysis capacity than the untreated enzyme, suggesting the important influence of ruptured bran surface on amplifying the hydrolysis effect of cellulase. Compared to the successive ultrasound stimulation on both cellulase and brown rice, ultrasound-assisted cellulase treatment on brown rice produced less glucose from rice bran, but induced similar textural properties of brown rice, possibly resulting from the simultaneously promoting effect of ultrasonication on cellulase and water diffusion. Ultimately, this study highlighted that the mild rice surface rupture is a crucial factor to display the promoted hydrolysis effect of ultrasonicated cellulase on brown rice. Ultrasound-assisted cellulase treatment potentially provides an effective strategy to improve the edible quality of brown rice.     

Preparation of cadmium‐containing brown rice grains as calibration standards for X‐ray fluorescence analysis of cadmium in rice grains

A preparation method for Cd‐containing brown rice grains as calibration standards was developed for X‐ray fluorescence (XRF) analysis of Cd in rice grains. Calibration standards were prepared by adding 10 g of base rice grains (from Japan) to 100 ml of methanol containing 5?100 µg of Cd. The mixture was heated, cooled, and stored in a silica gel desiccator. Seven grams of each calibration standard was packed into a polyethylene cup (32‐mm internal diameter and 23‐mm height) covered with a 6‐µm‐thick polypropylene film and then subjected to XRF analysis. The calibration curves of Cd in brown and white rice grains showed good linearity in 0.50?10 mg kg^?1. The detection limits of Cd in brown and white rice grains were 0.14 and 0.12 mg kg^?1, respectively. The slopes of the calibration curves for Cd in brown and white rice grains were slightly different owing to absorption effects. The absorption effects were corrected using the ratio of the intensity of Cd Kα to that of Rh Kα‐Compton scattering. After correction, the calibration curves of Cd in brown and white rice grains showed identical slopes. The spike test for 5 mg kg^?1 of Cd in white rice grains (from Thailand), using the corrected calibration curves, showed quantitative recoveries (92?97%). Copyright © 2013 John Wiley & Sons, Ltd.     

转基因水稻糙米中痕量铅和镉的交联羧甲基魔芋葡甘聚糖微柱预富集-GFAAS测定研究

建立了以交联羧甲基魔芋葡甘聚糖(CCMKGM)为微柱预富集-GFAAS测定转基因水稻糙米中痕量铅和镉的新方法。考察了溶液的pH值、样品流速和体积、洗脱液的浓度和体积及共存离子干扰等因素对CCMKGM微柱吸附重金属的影响。结果表明:在优化条件下,方法用于富集、测定转基因水稻及亲本糙米中Pb和Cd的检出限分别为0.11和0.002μg.L-1;测定大米标准参考物质中Pb和Cd的含量,结果与标准参考值相吻合。对转基因水稻及亲本糙米进行标准加入回收实验及测定,回收率分别在90%～103%和93%～105%范围。该研究可为转基因水稻中痕量Pb和Cd分析提供技术支持。     

Physicochemical properties of germinated dehulled rice flour and energy requirement in germination as affected by ultrasound treatment

Limited data are published regarding changes in the physicochemical properties of rice flours from germinated de-hulled rice treated by ultrasound. This work was undertaken to evaluate the effect of ultrasound treatment (25 kHz, 16 W/L, 5 min) on starch hydrolysis and functional properties of rice flours produced from ultrasound-treated red rice and brown rice germinated for up to 36 h. Environmental Scanning Electron Microscopy (ESEM) microimages showed that the ultrasound treatment altered the surface microstructure of rice, which helped to improve moisture transfer during steam-cooking. The flours from sonicated germinated de-hulled rice exhibited significantly (p < .05) enhanced starch hydrolysis, increased the glucose content, and decreased falling number values and viscosities determined by a Rapid Visco Analyzer. The amylase activity of the germinating red rice and brown rice displayed different sensitivity to ultrasonic treatment. The ultrasonic pre-treatment resulted in a significant reduction in energy use during germination with a potential to further reduce energy use in germinated rice cooking process. The present study indicated that ultrasound could be a low-power consumption method to modify the rheological behavior of germinated rice flour, as well as an efficient approach to improve the texture, flavor, and nutrient properties of steam-cooked germinated rice.     

Sonication increases the porosity of uncooked rice kernels affording softer textural properties,loss of intrinsic nutrients and increased uptake capacity during fortification

This work investigates the effect of sonication on brown and milled rice grains of both waxy and non-waxy varieties. We report herein the microstructural analysis of uncooked rice kernels under sonication and its effect on the textural properties. X-ray computed tomography results showed the formation of microporous surfaces and the creation of cracks and fissures. Sonication increased the % porosity of the rice samples allowing for easy penetration of water during the cooking process and promotes softer texture. Moreover, the effect of sonication in brown rice resulted to the decrease in endogenous iron and phosphorus contents but increased its capacity for iron uptake through fortification when sonicated rice is soaked in the mineral solution.     

原子吸收法检测脑梗塞患者头发中锌、铜、镁、锰

用原子吸收分光光度法测定脑梗塞患者 4 5例及健康对照者 2 0例头发中微量元素Zn ,Cu ,Mg ,Mn的含量。结果表明 ,脑梗塞组头发中Zn ,Cu ,Mg元素含量均显著低于正常对照组 (P <0 0 1) ,Mn元素的含量显著高于对照组 (P <0 0 1) ,揭示体内Zn ,Cu ,Mg ,Mn元素含量与脑梗塞发病存在一定关系。     

Fermentation of rice hull by Aspergillus japonicus under ultrasonic pretreatment

The application of ultrasound for treating rice hull used as the fermentation substrate for xylooligosaccharides production was investigated. Aspergillus japonicus CY6-1 was selected to produce cellulolytic and xylanolytic enzymes from untreated rice hull (RH) and rice hull treated with ultrasound (USRH-M). The hemicellulose yield was increased to 1.4-fold with ultrasound, and treatment time was greatly shortened from 24 h to 1.5 h at 80 °C and 300 W/28 kHz. The morphology of RH from various pretreatments was observed with field emission scanning electron microscope (FESEM), revealing the surface structure of USRH-M smoother than that of RH. USRH-M was much easier to be utilized by fungi, to extend the stability of enzyme activity and to increase activities of CMCase, β-glucosidase, and xylanase compared with those of untreated RH. The final fermentative products were xylotetraose, xylohexaose, and higher molecular weight xylooligosaccharides, achieving xylohexaose yield for USRH-M 80% higher than that for RH group.