石墨炉原子吸收光谱法测定保健品松花粉中痕量铅

实验通过采用优级纯以上试剂降低本底,多道程序清洗器皿控制污染,通过控制酸量改善测定铅的信噪比,降低检出限,引入基体改进剂磷酸二氢铵消除基体干扰.优化石墨炉检测条件下,松花粉样品中铅的加入平均回收率达到90％以上.使用标准物质(茶叶GBW10016)对该方法进行了验证,结果表明铅的测定值在标准物质的保证值范围内.该方法能...     

油菜叶片和冠层水平氮素含量的高光谱反射率估算模型

通过设计实验首先确定是否可以用油菜叶片反射率光谱预测其氮素含量,以及是否可以用预测的光谱特征值与氮素含量建立相关模型。实验结果表明,反射率光谱的转化形式R的一阶微分为预测油菜氮素含量的最佳形式,最佳波段选择与其他研究结果相似。短波红外光谱波段能较好预测氮素含量,但是选择的高相关性短波红外区域一般都较窄,因此可用高光谱和高辐射分辨率来准确描述油菜光谱特征。短波红外反射率的变化主要是由于植被化学信号的改变而引起的。直接太阳辐射率、观测设备、叶片振动以及大气湿度的细微变化都可能引起光谱一阶微分的变化。冠层反射率一阶微分R′建立的逐步回归模型拟合度较高。     

六种蜂花粉的红外光谱三级鉴别研究

采用傅里叶变换红外光谱(FTIR)结合二阶导数谱和热扰动下的二维相关红外光谱技术对6种不同花粉,即杏花花粉、油菜花粉、茶花花粉、西瓜花粉、荷花花粉和虞美人花粉,进行了快速无损的鉴别。结果表明,在一维红外光谱图上,不同花粉的蛋白质、脂肪和糖类物质的特征吸收峰在相对峰强和峰位上均存在一定的差异,在二阶导数谱上差异很明显。而在二维红外谱图上,由于6种花粉的自动峰及相关峰峰簇的位置和数量不同,其差别体现得更为明显和直观。因此,三级红外宏观指纹图谱法是鉴别不同蜂花粉种类的一种有效和快速检测方法。     

ALGAL, SPORES AND POLLEN ASSEMBLAGES FROM LATE PLEISTOCENE IN THE EAST PART OF THE CHINA SEA AND THEIR PALEOENVIRONMENTS

The paper deals with fossil spores, pollen and algae from the sediments of 70,00-12,000a B. P. in the eastern sea area of China, distinguishing three spores, pollen and algal zones. Zone Ⅰ indicates that the climate was cold, the sea level was lower, the continental shelf of theDonghai Sea (the East China Sea)was exposed as the plain with various grasses thickened and manylakes andswamps dotted in which lived abundant freshwater algae of Pediastrum, Zygnema, etc.The hills in the continental margin were covered by the dark coniferous forests of Abies, Piceaand Pinus. The climate of Zone Ⅱ was warm, resulting in the sea level rising and the con-tinental shelf submerged as neritic environment with a variety of diatoms, dinoflagllate andDictyocha. The vegetation of the hills in the continental margin became mixed forests ofconiferous and broad-leaf trees mainly composed of Pinus and Quercus. Zone Ⅲ indicatesthat the climate became cold again and the continental shelf was exposed as plain with thesame lan     

秦油2号油菜高产栽培中喷肥优化配方研究

采用二次饱和－Ｄ最优设计的方法，研究Ｓｒ（ＮＯ３）２（ｘ１）、ＫＨ２ＰＯ４（ｘ２）和Ｎａ２Ｂ４Ｏ７·１０Ｈ２Ｏ（ｘ３）叶面喷施对秦油２号油菜的产量效应，获得回归方程：ｙ＝２４７．４８５＋７．００４８ｘ１＋２．２９２４４ｘ２—９．８２６４６ｘ３—０．２５３５ｘ１ｘ２—１３．８５２４ｘ１ｘ３：—３．３７４７５ｘ２ｘ３＋２７．０５７５Ｘ２１—１６．３０３６ｘ２２—８．７６７８ｘ２３结果表明Ｓｔ（ＮＯ３）２。有明显的增产作用．ｘ１ｘ３的交互作用（效应）最大．通过计算机模拟．其最佳因子组合为Ｓｒ（ＮＯ３），０．１％、ＫＨ２ＰＯ４０．３％和硼砂０．０１％，预计产量可达２９６．４６ｋｇ／６６７ｍ２．     

Studies on the Peptides and Polysaccharides in Pollen

The peptides RP3I and PSPP1-4 were purified from the rape and the Papaver Somniferunpollens, respectively. Their sequences and physiological activities were determined and synthesized ex-cept PSPP1. The polysaccharides TAA-C and CPA-E were obtained from Typha Angustifilia andCodonopsis Pilosula pollens, respectively. Their partial characterization and structures were studied.     

Pollen discrimination and classification by Fourier transform infrared (FT-IR) microspectroscopy and machine learning

The discrimination and classification of allergy-relevant pollen was studied for the first time by mid-infrared Fourier transform infrared (FT-IR) microspectroscopy together with unsupervised and supervised multivariate statistical methods. Pollen samples of 11 different taxa were collected, whose outdoor air concentration during the flowering time is typically measured by aerobiological monitoring networks. Unsupervised hierarchical cluster analysis provided valuable information about the reproducibility of FT-IR spectra of the same taxon acquired either from one pollen grain in a 25 × 25 μm² area or from a group of grains inside a 100 × 100 μm² area. As regards the supervised learning method, best results were achieved using a K nearest neighbors classifier and the leave-one-out cross-validation procedure on the dataset composed of single pollen grain spectra (overall accuracy 84%). FT-IR microspectroscopy is therefore a reliable method for discrimination and classification of allergenic pollen. The limits of its practical application to the monitoring performed in the aerobiological stations were also discussed. Figure Traditional and innovative methods for the identification of airborne pollen grains     

高效液相色谱-质谱分离鉴定荧光试剂标记的脂肪酸

以2-(2-(10-蒽基)-萘[2,3-d]咪唑)-乙基-对甲苯磺酸酯(ANITS)作为柱前衍生化试剂,在Eclipse XDB-C8色谱柱上,梯度洗脱实现了20种游离脂肪酸(FFA)衍生物的完全基线分离。90℃下在DMF溶剂中以K2CO3作催化剂,选取衍生试剂摩尔数为脂肪酸的7倍,衍生反应40min可获得稳定的荧光产物。激发和发射波长分别为250nm和512nm。采用大气压化学电离源(APCI)正离子模式,实现了油菜蜂花粉中游离脂肪酸的质谱鉴定。所有脂肪酸的线性相关系数均大于0.9999,检出限为24.76~98.79fmol。     

Pollen-imprinted polyurethanes for QCM allergen sensors

Molecularly imprinted polymers for detecting plant pollen were designed as artificial recognition materials for quartz crystal microbalances in the gaseous phase. Imprints of birch (diameter, 25 μm) and nettle (diameter, 15 μm) pollen can be generated by polydimethylsiloxane stamping technique as proven by atomic force microscopy. If pollen grains are able to access the cavities and thus are incorporated, the resulting sensors display Sauerbrey-like negative frequency shifts. Non-Sauerbrey behaviour can be observed as soon as pollen is prevented from entering the selective hollows: this results in grain mobility on the electrode surface leading to frequency increases. Access to the cavities is determined by the diameter ratio between pollen grains and imprints as can be revealed during cross-selectivity measurements of nettle and birch pollen imprinted layers. When the amount of pollen grains on the electrode surface exceeds the number of available imprints, the excess particles move freely, resulting in positive, non-Sauerbrey frequency shifts. Dedicated to Prof. Dr. Ernst Kenndler on the occasion of his 65th birthday.