磁处理对大豆中大豆异黄酮的作用

采用不同磁场强度不同时间处理大豆萌发种子,通过分光光度计法测量大豆异黄酮的含量。研究结果表明：磁场可以改变大豆中大豆异黄酮的含量,在不同的磁场及处理时间条件下,大豆中大豆异黄酮的含量不同。其中150mT处理1h,100mT处理1．5h的大豆中大豆异黄酮含量最大,相比对照分别增加了9．3％,11．8％。该实验结果发现,磁场强度与处理时间的乘积为150mT·h时,大豆异黄酮含量最高。     

双波长法测定常用淀粉原料中直链淀粉、支链淀粉及总淀粉含量

建立了双波长法测定常用淀粉原料中直链淀粉、支链淀粉和总淀粉含量的方法。按照双波长测定的等吸收点作图法确定2种淀粉的测定波长和参比波长,直链淀粉的测定波长分别为630、480 nm,支链淀粉的测定波长分别为550、735 nm。结果表明,直链淀粉浓度在0~36 μg/mL、支链淀粉浓度在40~100 μg/mL范围内线性关系良好,符合比耳定律,具有较高的精确度和准确度。常用淀粉原料的总淀粉含量在66.51%~83.65%,其中绿豆淀粉和豌豆淀粉的直链淀粉含量比明显高于其他淀粉原料;糯米粉中的支链淀粉含量最高,其直链淀粉含量过低,导致吸光值太小而检测不出。     

Determination of molybdenum in plant tissue by graphite furnace atomic absorption spectrophotometry (GFAAS)

Abstract

The analysis of molybdenum in plant tissue using graphite furnace atomic absorption spectrophotometry (GFAAS) is described. The method involved wet digestion using a mixture of sulphuric, nitric and perchloric acids followed by a solvent extraction procedure. Molybdenum was extracted into di‐iso butyl ketone (DIBK) as the iron‐thiocyanate complex. The extract was then analysed for molybdenum by GFAAS.

The results of analyses of the reference plant materials (orchard leaves and citrus leaves) of the National Bureau of Standards (NBS) compared very well with the certified values. Other types of plant tissue were also analysed and the results correlated well with those obtained by an alternative method.     

Fiber‐optic spectrophotometry of cowpea nodules treated with nitrate or ammonium

Abstract

Cowpea nodules (Vigna unguiculata [L.] Walp. cv. CB5) were pierced with two opposing optical fibers (280 μm diameter), and absorbance spectra of 0.1 mm of nodule tissue were recorded from 415 to 600 nm using a modified spectrophotometer with a nodule sampling stage.

The nodule spectra exhibited two absorbance bands, a major band in the near‐UV (415–450 nm) and a lesser one in the green‐yellow region (510–585 nm); the latter exhibited a prominent peak at 550 nm. Nodule spectra were consistent with the superposition of the spectra of ferroleghemoglobin (Lb²⁺), oxyleghemoglobin (Lb²⁺‐ O₂), and cytochrome c (550 nm). The detection of leghemoglobin in vivo was confirmed by demonstrating the reversibility of binding of CO to Lb, and by comparing the spectra of live nodules with those obtained from anaerobic leghemoglobin preparations.

The effects on the nodule spectra of two successive applications (36 and 39 days after planting) of 5 and 10 mM NO₃ ^‐ or NH₄ ⁺ to the nutrient solution bathing the nodulated roots were determined. The spectra of NO₃ ^‐‐ and NH₄ ⁺‐treated nodules were indistinguishable; in each case the height of both the near‐UV and green‐yellow absorbance bands decreased with treatment. Treatment with N caused a significant reduction in the area of the green‐yellow absorbance band.

The spectra of green leghemoglobin pigments were obtained from senescent nodules; these exhibited a reduction in the height of the near‐UV absorbance band and a flattening of the green‐yellow band similar to that of nodules treated with N, but the broadening of the near‐UV band was greater in green nodules.     

紫外分光光度法测定农田土壤微生物生物量氮可行性初探

采用氯仿熏蒸浸提-紫外分光光度法和消化法比较测定了田间定位试验不同施肥处理土壤、添加植物残体土壤、添加葡萄糖土壤的微生物生物量碳、氮(SMBC,SMBN)。结果表明,当土壤微生物生物量氮含量较高时(>20 mg kg-1),采用分光光度法与消化法测定的SMBN具有显著正相关关系(P<0.05),但当SMBN量较低时(<20 mg kg-1)时,分光光度法测定与消化法测定的SMBN没有显著相关性。当土壤中添加麦秸和玉米秸时,土壤浸提液颜色较深(黄色),不适合采用分光光度法测定SMBN。因此,熏蒸提取–分光光度法测定SMBN,仅适于土壤浸提液无色透明、且SMBN含量较高的土壤。     

吐温-80对柴胡注射液紫外吸收光谱的影响

描述了吐温-80对柴胡注射液紫外吸收光谱的影响。实验结果表明,未加吐温-80（即聚山犁酯-80）的柴胡注射液,可得到符合国家兽药典要求的紫外吸收光谱,其他各项检测也合格。     

复方黄芪金银花颗粒的质量标准研究

建立了控制复方黄芪金银花颗粒的质量标准.采用薄层层析对颗粒中女贞子、金银花、黄芪、枸杞子进行了薄层鉴别以及双光束紫外-可见光分光光度法测定了颗粒中绿原酸的含量.结果显示,薄层鉴别方法专属性强,绿原酸在42.24～84.48μg/mL范围内具有良好的线性关系,标准曲线回归方程为:A=0.0053×C-0.0012(r=0.9999,n=5);样品在24 h内稳定,RSD=0.733%;加样平均回收率为102.094%,RSD=0.499%;该方法精密度高,RSD=0.382%.本质量标准可有效控制复方黄芪金银花颗粒的质量.     

微波加热分光光度法在磷酸根含量测定中的应用

在密闭条件下，研究了微波加热后水中总磷酸根含量的各种影响因素，建立了快速测定其含量的新方法。讨论了微波功率、微波时间、酸度等因素对分析测定的影响。用高档功率微波加热6min，用分光光度分析法进行测定，结果与标准方法相对照，经t-检验法及F－检验法检验，没有显著性差异，多次加标回收率在97．9％－108％之间，相对标准偏差≤1．3％。     

5-Br-PADN与Mn(Ⅱ)的显色反应及其应用

本文研究了在非离子表面活性剂存在下,5-Br-PADN与Mn(Ⅱ)的显色反应及其应用.所拟方法能满意地用分光光度法测定钢样中的微量锰.     

季铵盐类消毒剂的质量检测

对季铵盐类消毒剂进行定性定量检测以获取其质量信息。定性检测采取紫外分光光度法,定量检测采取两相滴定法。结果表明:除原料外的其他六种产品,中五种季铵盐含量达标。可见市场上流通的季铵盐类消毒剂存在不合格产品。