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The zinc and copper are separated from lead and tin based on the characteristics that ammonium hydroxide, zinc and copper form complex ions as well as ammonium hydroxide, lead and tin form precipitates. The effects of the acidity of zinc, lead and tin titrated with ethylene diamine tetraacetic acid (EDTA), added quantity of thiourea and ammonium fluoride as well as buffer solution on determination are tested. The test results showed that the pH value of solution acidity was 4.5~5.0 and selectivity of titration was higher when zinc was titrated with EDTA; pH value of solution acidity was 5.0~6.0 when determined lead and tin as well as the colors at titration end point changed sharply. The interference of coexisting ions could be avoided by adding sulfosalicylic acid. The determination range of this method is 0.50%~20%, relative standard deviations of zinc, lead and tin in tin bronze samples are all smaller than 2.0% through analysis as well as adding standard recovery is 97%~103%.
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| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
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