取明矾石矿样品(0.200 0g),在铂坩埚中与由碳酸钠和四硼酸钠(质量比2∶1)组成的助溶剂1.000 0g充分混匀,并在950℃熔融30min。取出冷却,用盐酸(1+9)溶液50mL浸出熔块,将所得溶液定容至100mL。此溶液用于电感耦合等离子体原子发射光谱法测定铁、钙、镁、铜、钛、铅、铬、镓的含量。另从此溶液中分取5.0mL,用水定容为100mL,供测定含量较高的钾、铝、硅。分别试验了用基体匹配法和加入2mg·L-1钇作内标的基体匹配法这两种条件以抑制基体效应。结果表明:在上述两种条件下测得的结果,其准确度相近;但后一条件下测得结果的精密度高于前一种条件。
The alunite ore sample(0.200 0g)was mixed thoroughly with 1.000 0g of the flux(Na_2CO_3+Na_4B_2O_7,with mass ratio of 2 to 1)in a Pt crucible and fused at 950 ℃ for 30 min.After cooling,the melt was taken up with 50 mL of HCl(1+9)solution and its volume was made up to 100 mL.This solution was used for ICP-AES determination of contents of Fe,Ca,Mg,Cu,Ti,Pb,Cr and Ga.For determination of K,Al and Si with higher contents,an aliquot(5.0mL)of the above sample solution was taken and diluted to 100 mL with water.To eliminate the matrix effect,2 conditions,i.e.,(1)the matrix matching method and(2) matrix matching method with addition of 2mg·L-1 of Y as internal standard,were tested separately.As shown by the testing results,accuracy of analytical results obtained under either of the 2 conditions mentioned above were attained at nearly the same level,but precision of the results obtained under the latter condition were better than those obtained under the former condition.