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分析步骤称取0.2000～1.0000克试样于银坩埚中,加入2～4克过氧化钠,混匀,用约1克过氧化钠覆盖,在700℃左右熔融4～5分钟,取出,稍冷,放入预先加有10毫升水的300毫升烧杯中。用25毫升4%酒石酸溶液浸取熔块,用热水洗净坩埚。煮沸,驱除剩余的过氧化物。趁热加入2毫升3%硫化钠和5毫升10%EDTA,煮沸并浓缩至30毫升左右,冷却至室温,移入50毫升量瓶中,用水定容,摇匀。干滤(弃去最初10毫升滤
Analysis step Weigh 0.2000 ~ 1.0000 g sample in a silver crucible, add 2 to 4 grams of sodium peroxide, mix, covered with about 1 gram of sodium peroxide, melted at about 700 ℃ for 4 to 5 minutes, removed, slightly cold , Into a 300 ml beaker pre-filled with 10 ml of water. Leach the frit with 25 ml of 4% tartaric acid and wash the crucible with hot water. Boil and remove excess peroxide. Add 2 ml of 3% sodium sulfide and 5 ml of 10% EDTA while hot, boil and concentrate to about 30 ml, cool to room temperature, transfer to 50 ml volumetric flask, dilute with water and shake well. Dry filter (discard the first 10 ml filter