1、beaker as in 13.1.1.Add35 mL HNO3(1+1), cover with a watch glass, and heat gentlyuntil dissolution is complete and oxides of nitrogen aredispelled. Cautiously add 10 mL of HClO4and continueheating (see Note 6). Evaporate to dense white fumes. Con-tinue fuming to near dryness.NOTE 6Handle HClO4in acc
2、ordance with practices E50 as follows:HClO4can be used safely, but only under carefully prescribed conditions.Dilute HClO4has the same hazardous properties as other strong acids, butthe concentrated acid, especially when it is hot, reacts rapidly and oftenwith violently explosive force with oxidizab
3、le materials. Only well-established procedures should be employed for HClO4oxidations and theprocedures should be followed exactly as written. Specially designedhoods are specified for handling HClO4fumes and any hood in whichHClO4may be fumed should not be used for other operations that permiteasil
4、y oxidizable material to collect in the ducts or blower.13.1.3.2 Cool slightly and dissolve salts in 35 mL HC1(1+3). Heat to boiling. Allow to cool again. Rinse watch glassand beaker with HC1 (1+3) and filter through a dry, highwet-strength, medium- porosity filter paper4into a volumetricflask. Wash
5、 the paper eight times with HC1 (1+3) and discardthe paper. Dilute to volume with HCl (1+3) and mix.13.2 Prepare a reagent blank by treating the same amount ofall reagents as directed in 13.1.2 or 13.1.3. Use reagents fromthe same lots for blank and test solutions.13.3 MeasurementUsing water as a ze
6、ro reference, aspi-rate calibration standards alternately until stable readings occur(within 2 %). Alternate readings: three samples, a standard,three samples and another standard, etc., until the absorbancefor all samples and standards have been determined at least4Whatman No. 54 or No. 541 has bee
7、n found suitable.FIG. 1 Ag in Cu concentrates: HNO3-HCl MethodE1898 133three times. (The absorbances should repeat within 2 %).Average all values for standards and samples. Plot curve ofabsorbance versus g/mL silver in the standards. Read sampleabsorbance from the curve to obtain g/mL values of thes
8、amples. Standards and blank must plot a straight line near zeroabsorbance on the graph.14. Calculation14.1 Convert the absorbance of the test sample solutionsand the reagent blank solution to micrograms of silver permillilitre of the final dilution volume by means of the calibra-tion curve. Calculat
9、e the content of silver as follows:E 5 CA 2 B!/D (2)where:A = g of silver per mL in the final test solution,B = g of silver per mL in the final reagent blank,C = final volume of test solution, mL,D = weight of dry sample in final volume, g, andE = silver content in the test sample, g/g14.2 Average t
10、he test results for the triplicate test sampleportions and round the results in accordance with Practice E29,to the nearest g/g, using the rounding method.15. Precision and Bias515.1 PrecisionThirty-one laboratories cooperated in test-ing these methods and obtained the statistical informationsummari
11、zed in Table 工的教育管理，党员干部的廉政意识明显增强。二是落实党风廉政建设责任制。结合民政工作实际，将各项廉政建设任务具体化、目标化，实行 “一岗双责”，落实到班子成员和各单位，强化了民政干部廉洁从政的意识。三是狠抓权力运行监控。坚持把民政系统所有行政权力全部纳入风险范围，确定风险等级和防范措施，确保各项民政工作公开公正、阳光透明。在下一步的党建工作中，我将团结协助民政局总支成员，进一步强化宗旨意识，深入开展“真情暖人心，满意在民政”活动，让每个服务窗口和单位、每个基层党组织都积极行动、积极参与，让每名共产党员都受到教育、得到提高、发挥作用，真正树立民政工作真情为民的良好形象。进
12、一步健全完善党组织阵地建设和制度建设，保障党员的民主权利和监督权利，不断增强党组织的凝聚力和战斗力。进一步加强党员干部的学习教育，把党员干部教育作为一项长期工作来强化，不断巩固和发展创先争优活动成果，全力推动民政局党建工作再上新台阶、再创新水平。these test methods may not be achieved.Element Maximum Level, %Arsenic 2.01These test methods are under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals,
13、 Ores, and Related Materials and are the directresponsibility of Subcommittee E01.03 on Precious Metals.Current edition approved June 10, 2003. Published December 2003. Originallypublished as E 1335 90. Last previous edition E 1335 946 (2001).2Annual Book of ASTM Standards, Vol 02.04.3Annual Book of ASTM Standards, Vol 14.02.4Annual Book of ASTM Stand
