中孔分子筛P1 23-SH分离富集-火焰原子吸收光谱法测定礼花弹中银

FAAS Determination of Silver in Fireworks After Separation and Enrichment by Adsorption on Mesoporous Molecular Sieve P123-SH

制备了中孔分子筛P123-SH,并对其用于吸附银离子的条件进行了探索。试验发现在温度为(20±1)℃,介质pH值为3.6时,振荡吸附10 min,吸附容量为15.97 mg·g^(-1),吸附率可达98.5%。吸附在中孔分子筛P123-SH上的银离子可用0.2 mol·L^(-1)盐酸-0.1 mol·L^(-1)硫脲溶液5 mL完全洗脱回收,用火焰原子吸收光谱法测定洗脱液中痕量银的含量。银的质量浓度在0.008～0.24 mg·L^(-1)范围内与其吸光度呈线性关系,方法的检出限(3σ)为0.64μg·L^(-1)。方法用于礼花弹样品中银含量的测定,加标回收率在97.5%～115.0%之间,相对标准偏差(n=7)为2.4%。

The mesoporous molecular sieve P123-SH was prepared,and the condition for adsorption of Ag~＋-ion was studied.It was found that in an aqueous medium of pH 3.6,the mesoporous molecular sieve P123-SH behaved to adsorb Ag~＋-ion strongly and equilibrium of adsorption was achieved by shaking for 10 min at the temperature of（20±1）℃,and the adsorptive capacity of Ag~＋-ion at equilibrium was 15.97 mg·g^-1,giving the adsorption rate of 98.5%.The Ag~＋-ion adsorbed on the surface of mesoporous molecular sieve P123-SH was completly desorbed with 5 mL of a mixed solution of 0.2 mol·L^-1 HCl and 0.1 mol·L^-1 thiourea,and the silver content was determined by FAAS.Linear relationship between values of absorbance and mass concentration of Ag^＋-ion was obtained in the range of 0.008--0.24 mg·L^-1,with detection limit（3σ） of 0.64μg·L^-1.The proposed method was applied to the determination of silver in firework,giving values of recovery in the range of 97.5%- 115.0%and RSD（n=7） 2.4%.