关于脂肪酸GC及GC-MS定性的问题？待分析样品：淡水鱼肌肉 脂肪酸 组成；文献中采用FID检测器进行检测，并用了sigma的混标进行定性。请问如何得知混标中37种 脂肪酸甲酯 的出峰时间呢？小弟的柱子是DB-5??下附文献及标品网址Approximately 50–100 mg lipids were then used for lipid class determinations by gas chromatography. Fatty acid methyl esters (FAME) were prepared by transesterification with borontrifluoride (BF3) in methanol at 70 °C. FAME was run on an Shimadzu GC-2010 gas chromatograph equipped with aflame ionization detector, a fused silica capillary column (30 m × 0.25 mm ID × 0.3 μm film, FFAP, Dalian Institute of Chemical Physics Chinese Academy of Sciences) and GC solution software. Hydrogen was used as the carrier gas (flow velocity: 1.0 ml min? 1). The injector temperature was adjusted to 260 °C, and the column temperature was increased from 160 °C to 230 °C at a rate of 2.0 °C min? 1 and then held at 230 °C for 15 min. The detector was maintained at 230 °C. The identifications of fatty acids were based on comparisons of retention times with known FAME standard mixtures (a 37-component FAME mix and menhaden oil, Sigma, Chemical Co, USA).标品网址：http://www.sigmaaldrich.com/cata ... ng=zh®ion=CN查看更多5个回答 . 24人已关注
如何选择Mott-Schottky曲线电位范围？谢谢！？各位大侠，朋友最近刚刚接触Mott-Schottky曲线，其中有多处不明白的地方，困扰许久，特来求助各位大侠，还望不吝指点，谢谢啦！麻烦了！? ?? ? 具体问题如下：? ???（1） 测试 M-S曲线时，电位范围该如何选择？（我的是一种新物质，无文献参考）电位不同是不是对Efb有很大影响？? ???（2）测试时，曲线最低点即起峰位点对应的纵坐标不为零，这样可以吗？（如图）? ???（3）根据M-S曲线测试得到的Efb位点与由线性扫描得到的起峰位点不同，该怎样解释呢？有文献解释为The discrepancy betweenVFB and the photocurrent onset is likely due to OER overpotential losses and voltage drops in the circuit. 我的是HER也可以这样解释吗？? ?? ? 谢谢诸位！万分感谢！未标题-2 拷贝.jpg查看更多6个回答 . 2人已关注
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