Vasylechko Volodymyr O, Gryshchouk Galyna V, Zakordonskiy Victor P, Vyviurska Olga, Pashuk Andriy V
Faculty of Chemistry, Ivan Franko National University of Lviv, 6 Kyryla and Mefodiya St., 79005 Lviv, Ukraine ; Department of Chemistry and Physics, Lviv Academy of Commerce, 9 Samchuka St., 79011 Lviv, Ukraine.
Faculty of Chemistry, Ivan Franko National University of Lviv, 6 Kyryla and Mefodiya St., 79005 Lviv, Ukraine.
Chem Cent J. 2015 Aug 27;9:45. doi: 10.1186/s13065-015-0118-z. eCollection 2015.
In spite of the fact that terbium is one of the rarest elements in the Earth's crust, it is frequently used for the production of high technological materials. At the result, an effective combination of sample preparation procedure and detection method for terbium ions in different matrices is highly required. The solid-phase extraction procedure with natural Transcarpathian clinoptilolite thermally activated at 350 °C was used to preconcentrate trace amounts of terbium ions in aqueous solutions for a final spectrophotometric determination with arsenazo III.
Thermogravimetric investigations confirmed the existence of relations between changes that appeared during dehydratation of calcined zeolite and its sorption affinity. Since the maximum of sorption capacity towards terbium was observed at pH 8.25, a borate buffer medium (2.5 · 10(-4) М) was used to maintain ionic force and solution acidity. Terbium was quantitatively removed from the solid-phase extraction column with a 1.0 M solution of sodium chloride (pH 2.5). The linearity of the proposed method was evaluated in the range of 2.5-200 ng · mL(-1) with detection limit 0.75 ng · mL(-1).
Due to acceptable recoveries (93.3-102.0 %) and RSD values (6-7.1) from spiked tap water, the developed method can be successfully applied for the determination of trace amounts of terbium ions in the presence of major components of water. Graphical abstractSorption of terbium(III) ions on clinoptilolite.
尽管铽是地壳中最稀有的元素之一，但它经常被用于生产高科技材料。因此，非常需要一种能有效结合不同基质中铽离子的样品制备程序和检测方法。采用在350℃下热活化的天然外喀尔巴阡斜发沸石进行固相萃取程序，对水溶液中的痕量铽离子进行预富集，最后用偶氮胂III进行分光光度测定。
热重研究证实了煅烧沸石脱水过程中出现的变化与其吸附亲和力之间存在关联。由于在pH 8.25时观察到对铽的吸附容量最大，因此使用硼酸盐缓冲介质（2.5·10⁻⁴М）来维持离子强度和溶液酸度。用1.0 M氯化钠溶液（pH 2.5）将铽从固相萃取柱上定量洗脱。该方法在2.5 - 200 ng·mL⁻¹范围内进行线性评估，检测限为0.75 ng·mL⁻¹。
由于加标自来水的回收率（93.3 - 102.0%）和相对标准偏差值（6 - 7.1）可接受，所开发的方法可成功应用于在水的主要成分存在下痕量铽离子的测定。图形摘要铽（III）离子在斜发沸石上的吸附。
