对于复杂矿石样品中Ca2+的含量,常规方法难以实现安全、简便的测量.有鉴于此,我们以HF/HCl混合消解矿石样品,采用饱和Na2CO3将消解产生的难溶CaF2转化为CaCO3;随后,以稀盐酸溶解CaCO3释放出Ca2+,以EDTA滴定其准确含量.该方法安全、便捷,具有良好的重现性、可靠性:相对标准偏差0.052％,加标回收率98.9％～99.8％.这一研究过程有助于提升学生的化学实践创新能力.%It's difficult to detect Ca2+ in complicated mineral samples with a simple and safe chemical method.The mineral samples in the mixture solution of HF-HCl were digested,and the formed precipitate of CaF2 to CaCO3 with saturated solution of Na2CO3 was translated.These CaCO3 could be dissolved easily in hydrochloric solution to release Ca2+,following an accurate titration with EDTA.The safety and convenience of this improved Ca2+ detection method was encouraging with a relative standard deviation of 0.052％and a recovery of 98.9％～99.8％.This investigation was beneficial to develop the students' innovation ability in chemistry.
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