离子色谱法测定爆炸残留物中无机离子

IC Determination of Inorganic Ions in Explosive Residues

提出了离子色谱法测定爆炸残留物中无机离子的方法。DIONEX IonPac AS11-HC型阴离子交换柱及淋洗液20mmol.L-1氢氧化钾溶液用于5种阴离子(Cl-、NO3-、NO2-、SO42-、ClO3-)的分离;DIONEX IonPac CS12A及淋洗液20mmol.L-1甲磺酸溶液用于5种阳离子(Na+、K+、NH4+、Ca2+、Mg2+)的分离。测定中均采用抑制电导检测器。10种离子的线性范围均为0.1～100mg.L-1,Cl-、NO3-、NO2-、SO42-和ClO3-5种阴离子的检出限(3S/N)分别为2.36,3.87,5.49,6.11,6.02μg.L-1,Na+、K+、NH4+、Ca2+和Mg2+5种阳离子的检出限(3S/N)分别为3.05,6.23,5.42,4.33,5.66μg.L-1。方法用于爆炸残留物中无机离子的测定,阴、阳离子的回收率分别在91.2%～106.2%%和90.3%～102.3%范围内,相对标准偏差(n=6)分别在2.1%～3.8%和1.1%～4.2%范围之间。

The contents of 5 anions and 5 cations in explosive residues were determined by ion chromatography （IC）. DIONEX IonPac AS11-HC Anion-exchange column with 20 mmol KOH solution as eluant was used for separation of the 5 anions, i. e. , Cl^- , NO3^- , NO2^- , SO4^2- and ClO3^-, and DIONEX IonPac CS12A cation-exchange column with 20 mmol·L^-1 methyl sulfonic acid as etuant was used for separation of the 5 cations, i. e., Na^＋, K^＋, NH4^＋, Ca^2＋ and Mg^2＋. Inhibitory conductivity detections were adopted in the determinations. Linearity was found in the same range of 0. 1- 100 mg ·L^-1 for all the 10 inorganic ions, with values of detection limit （3S/N） of 2. 36 μg·L^-1： for Cl^- , 3. 87 μg·L^-1 for NO3^- , 5.49 μg·L^-1 for NO2^- 6.11 μg·L^-1 for SO4^2- and 6.02μg·L^-1 for ClO3^- , 3.05 μg·L^-1 for Na^＋ , 6.23 μg·L^-1 for K^＋ , 5.42μg·L^-1 for NH4^＋ , 4.33 μg·L^-1 for Ca^2＋ and 5. 66 μg·L^-1 for Mg^2＋. The proposed method was applied to the determination of 10 inorganic ions in explosive residues, giving values of recovery in the ranges of 91.2%-106.2% and 90. 3%--102. 3%, and RSD （n=6） in the ranges of 2.1%-3.8% and 1.1%--4.2% for the anions and cations respectively.