2-（5-ブロモ-2-ピリジルアゾ）-[N-n-プロピル-N-(3-スルホプロピル）アミノ]フェノールを用いるプレカラム誘導体/逆相分配高速液体クロマトグラフィーによる鉄鋼の微量スズの定量

摘要

A novel method for the determination of trace amounts of Tin in iron and steel has been demonstrated by a reversed-phase HPLC using 2-(5-Bromo-2-pyridylazo)-5-(N-n-propyl-N-sulfopropylamino)phenol (5-Br-PAPS) as a derivatizing reagent. Certified reference materials of iron and steel were used to prepare digestive samples by decomposition with sulfuric acid and hydrogen peroxide solution followed by benzene extraction with iodide. The digested sample solutions were derivatized with 5-Br-PAPS solution in acetate buffer (pH 3.0) solution. Aqueous-methanol (45:55 w/w) containing 0.5 mol kg~(-1) acetic acid and 5.0X10_(-3)mol kg~(-1) of tetrabutylammonium bromide was used as an eluent and was monitored at 422 nm. A linear calibration was observed in the concentration range from lX10~(-7)mol dm~(-3) to lX10~(-6)mol dm~(-3). The detection limit (3 sigma) of Tin~(IV) was 2.3X10~(-8) mol dm~(-3), which corresponded to 2.7 ppm in iron and steel samples. The recoveries of Tin~(IV) added to the digested solution of iron and steel were with in 94.8 percent to 110 percent. The good recovery and high sensitivity indicate that the proposed system is of great promise for the determination of tin present in iron and steel.