Determination of aminophylline tablets
Take 20 tablets of anhydrous theophylline ┄, weigh them precisely, grind them fine, take an appropriate amount (about equivalent to aminophylline lOOmg), put them in a 200ml measuring bottle, add 0.1mol/L sodium hydroxide solution 20ml and water 60ml, shake for 10 minutes to dissolve aminophylline, dilute it with water to scale, shake well. After filtration and precision, the filtrate 5ml was taken and placed in a 250ml flask, diluted to scale with 0.01mol/L sodium hydroxide solution, shaken well, and determined by spectrophotometry (page 17, appendix). The absorbance was determined at the wavelength of 275nm, calculated according to the absorption coefficient (E) of C7H8N402.
The fine powder mentioned above (about 0.5g of aminophylline) was precisely weighed by ethylenediamine, dissolved at a low temperature and cooled by adding water 50ml, 8 drops of sodium alizarin sulfonate indicator solution was titrated with hydrochloric acid titration solution (0.1mol/L) until the solution showed yellow. Per lml hydrochloric acid titration solution (0.1mol/L) is equivalent to C2H8N2 of 3.005mg.
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The acquisition and processing of Keemun Black Tea
The processing technology of Qihong is fine. The bud leaves of one bud, two leaves and three leaves are picked as raw materials. After withering, kneading and fermentation, the bud leaves change from green to copper red, the aroma is transparent, and then baked until dry. After the black hair tea is made, it must be refined, and the refining process is complicated and takes time, such as wool sieving, shaking sieving, sieving, door tightening, sieving, cutting, wind selecting, picking, fire replenishing, breeze cleaning, spelling and packing. The shape of high-grade Qihong is tight and thin, the color is dark, the tea is red after brewing, and the aroma is fresh and fragrant.
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Processing Technology of Sichuan Border Tea
The production of border tea in Sichuan has a long history. The "Tea-Horse Law" was carried out by the officials of all dynasties since the Song Dynasty, and the "Tea-Horse Division" was set up in Ya'an, Tianquan and other places in Sichuan Province in the Ming Dynasty (AD 1371-1541). South roadside tea is made by cutting the branches and leaves of tea trees. The raw materials of fresh leaves of South roadside tea are thicker and old, which can be picked by hand or cut by knife, and the old leaves or current year branches and leaves can be picked by hand; the knife cuts the mature new branches and leaves of the current season or year. South roadside tea can be divided into Maozhuang tea and Zhuangzhuang tea due to different processing methods. Pick the fresh branches cut off
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