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БрС30铅青铜中铅的测定,我们采用硝酸分解试样后(盐酸和过氧化氢分解不掉),硫脲掩蔽铜,氟化铵(或氟化钠)掩蔽铁、铝、硫、钙等,在 pH5～6的情况下,加入过量的 EDTA-钠络合铅,用硝酸铅返滴过量的 EDTA-钠,以二甲苯酚橙为指示剂。终点明显,手续简便,操作速迅。虽有镍、锌、锰等没能掩蔽,但在此合金中一般含量极微,并不影响本法测定。
БрС30 Determination of lead in lead bronze, we use nitric acid to decompose the sample (hydrochloric acid and hydrogen peroxide decomposition can not afford), thiourea masking copper, ammonium fluoride (or sodium fluoride) masking iron, aluminum, sulfur, calcium, In the case of pH5 ~ 6, add excessive EDTA - sodium complex lead, lead nitrate with excessive return of sodium EDTA, xylenol orange as an indicator. Obvious end, the procedure is simple, fast operation. Although nickel, zinc, manganese, etc. can not be masked, but the general content of this alloy is minimal, does not affect the determination of this Act.