Hohai University

China Pharmaceutical University

Qingxia Li

Zhiwei Li

Yang Xiao

Hongwu Tang

Yuanqiang Zhang

Yubin Zhang

Miao Zhang

Saiyu Yuan

Provided are four crystal forms, A, B, C and D, of demethyleneberberine hydrochloride, and a preparation method therefor, and further provided are X-ray powder diffraction characteristic absorption peaks, infrared absorption peaks and DSC spectra of the four crystal forms. The X-ray powder diffraction characteristic diffraction peaks of the crystal forms are at about 8.205&#xb0;, 8.805&#xb0;, 10.817&#xb0;, 14.835&#xb0;, 15.479&#xb0;, 16.668&#xb0;, 17.492&#xb0;, 18.529&#xb0;, 20.656&#xb0;, 21.536&#xb0;, 23.538&#xb0;, 25.657&#xb0;, 26.192&#xb0;, and 28.808&#xb0;. A preparation method for the four crystal forms of the demethyleneberberine hydrochloride is also involved. The preparation method has a simple process, a high yield and a low cost; and has a high product purity and a stable quality.

Crystal forms of demethyleneberberine hydrochloride and preparation method therefor

The present invention discloses a device for measuring adsorption/desorption of contaminants onto surface bed sediments and a method of using the device. The measurement device includes a sediment sample disc, a sample holder, a reaction cylinder, a liquid collection cylinder, and a liquid circulating member from inside to outside, the liquid circulating member consisting of rubber pipes and a peristaltic pump. According to the method of using the device for measuring the adsorption/desorption of contaminants onto surface bed sediments, the full contact of bed sediments with pore water and the full exchange of overlying water with pore water are realized through liquid circulation without changing the arrangement modes of the bed sediments; any thickness of bed sediments can be performed on experiments, particularly for thin-layer bed sediments; and natural permeation and accelerated permeation of pore water through bed sediments can be switched simply by adjusting the flow rates of the peristaltic pump and by opening/closing of vent holes. Adsorption characteristic parameters obtained through the device and the method provide, for water quality models, data support which conforms to the natural existing condition of bed sediments and is more scientific and reasonable, and the device and the method achieve significant environmental benefits.

Device for measuring adsorption/desorption characteristic of surface bed sediments on contaminants and method of using the device

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Jiangsu, China

Qingxia Li