高温水解-离子色谱法测定氮化硅中的氟和氯

IC Determination of Fluoride and Chloride in Silicon Nitride After Pyrohydrolysis

采用高温水解-离子色谱法测定氮化硅中氟和氯的含量。氮化硅样品经1 050℃高温水解,氢氧化钠溶液吸收挥发性氟化物和氯化物,使待测元素以相应阴离子形式存在。以8.0mmol·L^(-1)碳酸钠-1.0mmol·L^(-1)碳酸氢钠混合液为淋洗液,抑制型电导检测器测定。F^-和Cl^-的线性范围依次为0.10~1.00mg·L^(-1),1.00~10.00mg·L^(-1),检出限(3σ)依次为0.017,0.026mg·L^(-1)。方法应用于氮化硅样品的分析,测定值与能量散射X射线荧光法测定结果相符,测定值的相对标准偏差(n=7)小于4.0%。用标准加入法进行回收试验,测得回收率在84.5%~106%之间。

IC was applied to the determination of fluoride and chloride in silicon nitride after pyrohydrolysis.Sample of silicon nitride was pyrohydrolyzed at 1 050 ℃,and the volatile fluoride and chloride produced were absorbed by sodium hydroxide solution forming anions of F^- and Cl^- in solution,and determined by ion chromatography.8.0 mmol·L^-1 Na_2CO_3-1.0 mmol·L^-1 NaHCO_3 mixed solution was used as eluant,and restraining conductance detector was used in determination.Linearity ranges of F-and Cl-found were between0.10-1.00mg·L^-1 and between 1.00-10.00mg·L^-1 with detection limits（3σ）of 0.017,0.026 mg·L^-1,respectively.The proposed method was applied to the analysis of silicon nitride sample,giving results in consistency with the values obtained by EDXRFS,and values of RSD′s（n=7）found were all less than 4.0%.Test for recovery was performed by standard addition method,giving values of recovery in the range of 84.5%-106%.