悬浮液进样—火焰原子吸收光谱法测定玉米中的锌和铁

本文提出了一种悬浮液进样－火焰原子吸收光谱法测定玉米面中锌,铁的新方法。将玉米面悬浮于琼脂胶体中,直接喷入空气－乙炔火焰中,用标准加入法测定,测定结果与灰化法一致。方法简便,快速。     

悬浮液进样-火焰原子吸收光谱法测定玉米面中的锌和铁

本文提出一种悬浮液进样-火焰原子吸收光谱法测定玉米面中锌、铁的新方法.将玉米面悬浮于琼脂胶体中,直接喷入空气-乙炔火焰中,用标准加入法测定,测定结果与灰化法一致.方法简便、快速.     

火焰原子吸收光谱法测定锑精矿中铅

本文介绍了火焰原子吸收光谱法测定锑精矿中铅。研究了样品制备方法及共存在元素的干扰，用王水－氢溴酸溶解样品，加入酒石酸抑制锑的水解，试液用空气－乙炔火焰原子吸收光谱法测定。相对标准偏差小于１％，此法优点是干扰少、准确度高、快速和简便等。用本法测定锑精矿中铅，获得满意的结果。     

火焰原子吸收光谱法测定茶叶中的钾、钠、铷

本文报道了空气－乙炔火焰原子吸收光谱法测定茶叶中钾,钠,铷的含量。茶叶采用硝酸消解,方法简单,快速,回收率为９９．９％－１０５．２％,相对标准偏差为２．７８％－８．９６％。     

原子吸收光谱法测定中成药阿胶中铜、铬、镉、铅、砷、锑、锡和汞

本文以５０ｍｌ比色管作消化容器，硝酸－高氯酸混酸消化中成药阿胶，采用火焰原子吸收法测定其中的铜；石墨炉法测定其中的铬、镉、铅；氢化物法测定其中的砷、锑、锡。以硝酸－硫酸加过氧化氢水浴加热消化处理样品、采用冷原子法测定其中的汞，均取得较满意的结果。     

火焰原子吸收光谱法测定磁化杯中铅,镉和铁

本文研究了火焰原子吸收光谱法测定磁化杯陶瓷内胆中Ｐｂ、Ｃｄ和Ｆｅ含量的方法。样品经粉碎，用硝酸－高氯酸混合液进行消解后测定。     

原子吸收光谱法分析稀土元素的进展

本文从火焰、普通石墨管、热解涂层石墨管、钽带或钽舟、难熔金属碳化物石墨管、衬钽箔或片石墨管和钽平台－石墨管原子化器，综述了近几年来原子吸收光谱法分析稀土元素的进展。火焰原子吸收法测定稀土元素的灵敏度比大多数非稀土元素低；电热原子吸收法测定稀土元素的原子化温度、记忆效应和灵敏度和原子化器的组分关系极大，钽平台－石墨管试验效果最佳。     

原子吸收光谱法测定金属原子簇化合物中铬

报道了利用火焰原子吸收谱法测定金属原子簇化合物中铬,用钠离子消 除共存元素干扰,本法简便、快速,具有良好的准确度和精密度,相对标准偏差为0．60％－0．67％,回收率为100％－103％。     

悬浮液进样-原子吸收法测定中药材中铜、锌、铁

本文提出了一种悬浮液进样－火焰原子吸收法测定中药材－－怀药（怀山药、怀牛膝、怀菊花）的新方法。并成功地进行了Cu,Zn,Fe的测定。将粉碎后的怀药悬浮于琼脂胶体中制成悬浮液，对悬浮剂的选择及化不干扰的消除进行了考察。将试液喷入空气－乙炔火焰中，用标准加入法测定，结果与HNO3＋H2SO4＋HClO4处理法一致。t检验结果表明：两种样品处理方法之间无显著性差异，可以采用悬浮液进样法取代HNO3＋H2SO4＋HClO4处理法，该方法快速简便、安全，有效，结果令人满意。     

火焰原子吸收法测定肥料中的铬

本文介绍了应用火焰原子吸收法测定肥料中铬的含量,对样品的前处理方法进行了探讨。结果表明,采用硝酸－高氯酸－氢氟酸消化法准确,可靠,方法的回收率为９７％￣１０１％,结果令人满意。     

悬浮液进样-原子吸收光谱法测定核桃粉中的钙、铁和锌

采用悬浮液进样技术应用于原子吸收光谱法,测定了核桃粉中的钙、铁和锌的含量.将核桃粉悬浮于琼脂胶体中制成悬浮液,直接喷入空气-乙炔火焰,用标准加入法测定,将实验结果与灰化法结果进行了比较,经t检验,在显著性水平a=0.05时两种方法无显著性差异,相对标准偏差≤6.1%,结果吻合较好.该方法简便,快速,灵敏度高,准确性好.     

微波消解-原子吸收分光光度法测定魔芋粉中铜、铁、锰、锌的含量

将硝酸和过氧化氢放入聚四氟乙烯密闭罐中，置于家用微波炉内，微波消化魔芋粉，火焰原子吸收分光光度法测定铜、铁、锰、锌的含量。回收率为95．2％－106．4％，相对标准偏差为1．0％－3．9％。方法快速、简便，具有良好的精密度和准确度。     

火焰原子吸收法测定小麦品种籽粒中铁锰锌含量

用火焰原子吸收分光光度法,测定6种不同类型的冬小麦品种籽粒中铁、锰、锌微量元素的含量。结果表明铁、锰、锌的回收率分别为10309%,10290%和10119%,相对标准偏差(RSD)分别在394%,167%和269%以内,并以GBW08503小麦粉标准样品进行比较测定,结果满意。该方法简便、快速、准确。测定结果为研究小麦品种籽粒中微量元素的含量与小麦品质的关系提供依据。     

火焰原子吸收法测定吉林地区63种食物中锌铜铁的含量

用火焰原子吸收法对吉林地区６３种食物中锌、铜、铁的含量进行了测定。结果表明，肝、瘦肉及蛋黄中上述元素含量较多，植物性食物次之，而水果类含量甚微。在各种食物中这三种元素的含量呈正相关，加工精制的面粉会使其含量下降。     

Determination of carotenoid and tocopherol content in maize flour and oil samples using near-infrared spectroscopy

Abstract

Secondary metabolites are important components in terms of nutrition and health. Carotenoids and tocopherols, two groups of the fat-soluble components, are also included in this category. There is an increasing interest in the detection of secondary metabolites with near-infrared spectroscopy. However, the number of scientific studies for the detection of these components, especially for tocopherols in corn flour or oil samples by near-infrared reflectance spectroscopy is rather limited. This study was carried out to determine the amount of carotenoids and tocopherols in flour and oil samples of 250 different maize genotypes by near-infrared reflectance spectroscopy using the partial least squares regression modeling method. Liquid chromatography mass spectrophotometry was used as a reference method in order to determine the contents of five carotenoids and four tocopherol subcomponents. The estimation models were created by using the spectral data collected from ground samples, and oil samples extracted from the same flour; along with the results of the reference analysis. The reliability of these models was tested by external validation (n?=?50). The prediction models generated by the spectra taken from corn flour yielded more successful results than the models created with the spectra taken from the oil samples. Among the models compared, the one developed with the spectra taken from flour samples for lutein was the most successful. It is seen that the estimation models generated from flour samples can be used for screening purposes, though different approaches are needed to increase the success of models.     

Influence of nanometer scale film structure of ZDDP tribofilm on Its mechanical properties: A computational chemistry study

We investigated the influence of a nanometer scale film structure of a tribofilm generated from zinc dialkyldithiophosphate (ZDDP) anti-wear additive on its mechanical properties using a combined molecular dynamics (MD) and finite element (FE) method. The frictional behavior of an interface between a native iron oxide layer on steel surface and zinc metaphosphate - regarded as a model material of ZDDP tribofilm - was firstly studied using the MD method. The results showed that the iron atoms in the oxide layer diffused into the phosphate layer during the friction process. The zinc atoms in the phosphate layer also diffused into the oxide layer. Significant interdiffusion of iron and zinc atoms was observed with increasing simulation time. Thus, metallic phosphate with a gradient composition of iron and zinc atoms was formed on the phosphate/oxide interface. We then constructed an axisymmetric nanoindentation simulation model from the MD-derived structures at a certain simulation time and carried out a FE calculation. As a result, we found that the rubbed ZDDP tribofilm, including the phosphate with the gradient composition of metallic atoms, showed larger contact stiffness and hardness. The combined MD/FE simulation indicates that the tribofilm becomes stiffer and harder due to the interdiffusion of iron and zinc atoms on the tribofilm/oxide interface. We have found that the gradient composition formation in ZDDP tribofilm during friction process influences on its mechanical properties.     

FAAS测定电解镉中的Zn、Cu和Fe

采用火焰原子吸收光谱法测定电解镉中铜、铁和锌的方法,确定了最佳仪器工作条件和样品处理方法.在选择好的实验条件下.测定铜的特征浓度为0.006#g/mL/1%吸收;铁的特征浓度为0.015μg/mL/1%吸收;锌的特征浓度为0.0031μg/mL/1%吸收.回收率分别为铜97.5%-98.0%,铁99.1%-100.2%,锌97.4%-99.1%.     

应用近红外光谱技术实现转双价基因(Cry1Ab/Cry2Aj-G10evo)玉米的快速识别

转基因技术在过去的几十年里快速发展, 然而此项技术对生态环境、伦理道德等可能带来的影响尚存争议,因此针对农作物的转基因成分检测和鉴别的相关技术研究十分重要。本研究以转双价基因(cry1Ab/cry2Aj-G10evo)玉米籽粒和玉米面粉为研究对象,采用近红外光谱仪采集900～1 700 nm波段范围的光谱,结合 Savitzky-Golay(SG)平滑算法对提取出的光谱数据进行去除噪声处理。基于全波段光谱和PCA主成分分别建立了偏最小二乘判别分析(PLS)和支持向量机判别模型(SVM)。试验结果表明,在转基因玉米籽粒全谱的判别分析模型中,SVM判别模型效果要优于PLS判别模型,SVM模型识别正确率达到90%以上,PLS的模型识别率只有85%左右。以PCA降维后建立的模型中,SVM模型也取得了最优的效果,建模集和预测集识别正确率达到100%。虽然转基因玉米在研磨加工后外源蛋白和DNA有所下降,但是转基因玉米粉末基于全波段光谱建立的SVM模型的建模集正确率仍有90.625%。结果表明应用近红外光谱技术集合化学计量学方法对转基因玉米的鉴别是可行的,为转基因玉米乃至其他转基因农产品的鉴别提供了技术支持,具有重要的理论意义和应用价值。     

湿法消解-火焰原子吸收光谱法测定黑种草籽中的4种金属元素

黑种草籽经湿法消解,用火焰原子吸收光谱法测定Cu、Fe、Mn、Zn的含量。该方法快速、简便、准确,4种金属的回收率为97.85%—101.95%,RSD为0.68%—2.08%,结果表明,黑种草籽中铁、锌元素含量较高。