维、哈、汉三种不同民族性别的人发中微量元素含量测定

本文采用火焰原子吸收法分别对４００例汉、维、哈三种不同民族,不同性别的人发中,微量元素Ｋ、Ｎａ、Ｃａ、Ｍｇ、Ｚｎ、Ｆｅ、Ｃｕ和Ｓｒ九种元素的含量进行测定,为开展不同民族学生的身体健康研究提供了有益的资料。     

高效液相色谱法测定染发剂中的22种染料成分

建立了染发剂中22种染料成分的高效液相色谱测定方法。使用Discovery RP-Amide C16柱(250 mm×4.6 mm,5 μm),以乙腈-0.025 mol/L磷酸盐缓冲液(pH 6.0,含0.1%的庚烷磺酸钠离子对试剂)为流动相,流速为1.0 mL/min;使用二极管阵列检测器(DAD),检测波长为260 nm和280 nm,柱温为25 ℃。该方法除了对低浓度的甲苯-2,5-二胺硫酸盐、2-甲基雷锁辛和N,N-二乙基甲苯-2,5-二胺HCl外,对其他各组分的含量测定值的相对标准偏差(RSD)均小于10%,加标回收率为77.6%～122.8%。该方法简便、准确、快速,适于氧化型染发剂中染料成分的检测。     

Two New Natural Methoxyflavonoids from Leaves of Murraya paniculata(L.) Jack

Two new natural methoxyflavonoids and two known methoxyflavonoids were isolated from the ethanol fraction of the leaves of Murraya paniculata(L.) Jack. The two new natural methoxyflavonoids were elucidated as 2'-hydroxy-3,4,5,3',4',6'-hexamethoxychalcone(1) and 6,7,8,3',4'-pentamethoxyflavanone(2) on the basis of ¹³C NMR and mass spectra. The two known methoxyflavonoids were identified as 3'-hydroxy-5,7,4'-trimethoxyflavone(3) and 2'-hydroxy-3, 4, 4', 6'-tetramethoxychalcone(4).     

基于叶片光学属性的作物叶片水分含量反演模型研究

叶片含水量是反映作物生理特性的一个重要参数,对生态环境的研究具有重要意义。采用小波分析方法,分析叶片含水量对反射率的影响特征,建立综合利用多波段信息的作物叶片水分含量反演模型。基于PROSPECT模型的辐射传输理论,推导出由叶片反射率光谱的小波系数反演叶片水分含量C_W的理论模型。利用六种常用的小波函数,对叶片组分水、干物质和白化基本层的吸收光谱进行小波分解。选取对水分变化最敏感,同时对其他组分不敏感的分解尺度和波段位置,找到能稳定突出水的光谱特征的小波系数。结果表明：bior1.5小波函数在尺度为200 nm,波段位置为1 405和1 488 nm的小波系数具有上述特征。建立由叶片反射率光谱的bior1.5小波系数反演叶片水分含量C_W的反演模型,模型有两个转换系数a和Δ都受叶片结构参数N的影响。利用PROSPECT模型生成模拟光谱数据集,校正建立的叶片水分含量反演模型中的两个转换系数a和Δ,并与LOPEX93实验光谱数据集结合验证反演模型。结果表明：反演模型不仅比传统基于植被指数的统计模型在精度上有提高(反演值与实测值的R2最高达到0.987),而且更加稳定,普适性更高。研究表明,小波分析方法在利用高光谱数据反演作物叶片水分含量方面具有独特的优势。     

介绍一个针对非化学专业的化学科普实验——头发中微量元素的测定

结合中国科学技术大学的学期改制,在夏季学期面向全校非化学专业的低年级本科生开设了“生活中的化学科普实验”公选课程,课程内容多为与生活密切相关的热点问题。“头发中微量元素的测定”是其实验项目之一。该实验将学生自己的头发作为分析对象,合理地设计教学内容和实验步骤,以期激发学生对化学实验的兴趣,提高学生对化学学科的认识。     

Determination of methamphetamine and amphetamine in abusers' plasma and hair samples with HPLC-FL

This paper describes highly sensitive HPLC methods for the determination of amphetamine (AP) and methamphetamine (MP) in abusers' plasma and hair samples. AP and MP were derivatized with the fluorescent reagent, DIB-Cl, to yield a highly fluorescent DIB-derivatives of AP and MP, which were then analyzed by HPLC with fluorescence detection at excitation and emission wavelengths of 325 and 430 nm, respectively. The separation was achieved on an ODS column with isocratic mobile phases composed of acetoniltrile and citrate buffer (55:45, v/v) for plasma samples and of acetonitrile-methanol-citrate buffer (45:20:37.5, v/v/v) for hair samples. The limits of detection were less than 0.87 ng/mL and 0.12 ng/mg in plasma and hair samples, respectively, for both AP and MP. The methods were then applied to the determination of MP and its metabolite AP in plasma obtained from two cases of illegally ingested MP and in one of the cases' hair received later. Case I was treated with dialysis; samples before and after dialysis were analyzed by the described method. After dialysis for 5 h, the total plasma levels of AP and MP decreased from 720 to 190 ng/mL. For case II, MP and AP levels were monitored for 3 days after digestion. Total plasma levels decreased from 57 ng/mL in the day of digestion to 11 ng/mL after 3 days. In hair samples, AP and MP could also be detected in very low concentrations.     

水杨基萤光酮－溴化十六烷基三甲基铵分光光度法测定锌

水杨基萤光酮－溴化十六烷基三甲基铵分光光度法测定锌黄青瑜，童式国，刘小虎，杨映辉（四川大学化学系，成都６１００６４）关键词：锌，水杨基萤光酮，人发，分光光度法微量锌的测定方法是比较多的，如近年来发展较快的有高灵敏显色的萤光酮衍生物等。而水杨基萤光酮，...     

Determination of replacement of some inorganic elements in pulvinus of bean (Phaseolus vulgaris cv. Gina 2004) at chilling temperature by the WDXRF spectroscopic technique

In this study, bean seedlings (Phaseolus vulgaris cv. Gina 2004) were exposed to chilling temperatures until leaves are wrinkled (9 day), that is, showed nyctinastic movement. Pulvinus were subsequently were cut from the leaves. Concentrations of inorganic elements (P, S, Cl, K, Ca, Cu) in the pulvinus were measured by wavelength-dispersive X-ray fluorescence (WDXRF) spectrometry. Results indicated that concentration change (%) was not significant for Ca (0.82) but it was significant for K, P, Cl, S, and especially Cu concentrations (5.4%, 12.8%, 40.2%, 43.7%, 365%, respectively) in pulvinus of plants exposed to chilling temperature compared with control group.We hypothesize here the presence of association between nyctinasti movement brought about by pulvinus at chilling temperature in bean and changes of K, P, Cl, S and especially Cu concentrations measured by WDXRF analysis method.     

Analysis of anabolic steroids in hair by GC/MS/MS

A simple and sensitive gas chromatography/tandem mass spectrometry (GC/MS/MS) method is described for the detection of anabolic steroids, usually found in keratin matrix at very low concentrations. Hair samples from seven athletes who spontaneously reported their abuse of anabolic steroids, and in a single case cocaine, were analyzed for methyltestosterone, nandrolone, boldenone, fluoxymesterolone, cocaine and its metabolite benzoylecgonine. Anabolic steroids were determinate by digestion of hair samples in 1 m NaOH for 15 min at 95 degrees C. After cooling, samples were purificated by solid-phase and liquid-liquid extraction, then anabolic steroids were converted to their trimethylsilyl derivative and finally analyzed by GC/MS/MS. For detection of cocaine and benzoylecgonine, hair samples were extracted with methanol in an ultrasonic bath for 2 h at 56 degrees C then overnight in a thermostatic bath at the same temperature. After the incubation, methanol was evaporated to dryness, and benzoylecgonine was converted to its trimethylsilyl derivative prior of GC/MS/MS analysis. Results obtained are in agreement with the athletes' reports, confirming that hair is a valid biological matrix to establish long-term intake of drugs.     

遥感反演时间序列叶面积指数的集合卡尔曼平滑算法

基于MODIS LAI产品数据集(MOD15A2)构建经验性的LAI动态模型,以LAI作为连接参数,将LAI动态模型与植被辐射传输模型MCRM2相耦合,提出了将耦合模型与时间序列MODIS反射率观测数据集(MOD09A1)同化进行LAI反演的方案.将集合卡尔曼平滑(EnKS)方法引入到LAI同化反演中,为更好地评价该算...