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Vortex‐assisted liquid–liquid microextraction of strontium from water samples using 4′,4″(5″)‐di‐( tert ‐butylcyclohexano)‐18‐crown‐6 and tetraphenylborate
Author(s) -
Wang ChinYi,
Chang DaAn,
Shen Yuzhou,
Sun YuhChang,
Wu ChienHou
Publication year - 2017
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201700205
Subject(s) - tetraphenylborate , chemistry , extraction (chemistry) , nitric acid , strontium , chromatography , detection limit , aqueous solution , analytical chemistry (journal) , ion , inorganic chemistry , organic chemistry
A vortex‐assisted liquid–liquid microextraction method was developed for the chromatographic determination of strontium in aqueous samples. In the method, strontium was complexed with 4′,4″(5″)‐di‐( tert ‐butylcyclohexano)‐18‐crown‐6 in the presence of tetraphenylborate as the counter anion, which increased the hydrophobicity of the ion‐association complex, resulting in its improved extraction into 1‐octanol. Strontium from the organic phase was stripped with nitric acid back to aqueous solution and determined by ion chromatography. The optimum microextraction conditions were as follows: 2.0 mL aqueous samples with 3 mM tetraphenylborate; 150 μL of 1‐octanol as the extractant phase with 10 mM DtBuCH18C6; vortex extraction time for 10 s; centrifugation at 6000 rpm for 4 min; stripping by 0.1 M nitric acid. Under the optimum conditions, the detection limit for strontium was 0.005 mg/L. The calibration curves showed good linearity over the range between 0.01 and 2.5 mg/L. Intra‐ and interday precisions of the present method were satisfactory with relative standard deviations of 1.7 and 2.1%, respectively.