Xi'an Jiaotong University

Rui Zhang

Yan Zhao Liu

Min Wu

Jiaqi Wang

Liyun Kong

Lina Zhang

Menglu Wu

Zhongming Xue

Lijuan Shi

Wei Gou

Guoli Li

Feifei Qi

Li Geng

Ruiqiang Zhang

Le Ma

A method for simultaneously determining fat-soluble vitamins and carotenoids in serum, and belonging to the technical field of analytical chemistry, includes an ionic liquid (IL) or a binary mixed solvent composed of an IL and another solvent is adopted as an extractant; the biological samples are pre-treated by liquid-liquid extraction (LLE) and then detected by high-performance liquid chromatography (HPLC); retinyl acetate and trans-&#x3b2;-apo-8'-carotenal are adopted as the internal standards for fat-soluble vitamins and carotenoids, respectively; and the internal standard method is adopted to establish standard curves for quantification based on the retention time and the UV-Vis absorption spectrum. Compared with the existing methods, in the disclosure, the pretreatment process is simple and easy to be conducted, the sample can be prepared in a short time, and the toxic and harmful organic solvent is used at a reduced amount.

Method for simultaneously determining fat-soluble vitamins and carotenoids in serum

A low-power-consumption high-speed zero-current switch includes a delay controller, a driving stage and a power transistor MN, wherein: an input of the delay controller is connected with an external clock CLK, an output of the delay controller is connected with an input of the driving stage, and an output of the driving stage is connected with a gate of the power transistor MN; the delay controller includes a gate signal generator, a sampling circuit and a current controller, and three of which form a negative feedback loop for stabilizing the turn-on voltage Vand the turn-off voltage Vto 0, so that when the power transistor MN is turned on or off, the source-drain voltage thereof is 0. The present invention no longer uses a high-power-consumption high-speed comparator, but uses a low-power-consumption delay controller to generate turn-on and turn-off signals of the power transistor.

Low-power-consumption high-speed zero-current switch

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Shaanxi, China

Rui Zhang