M. Takaya, Development of an analytical method for beryllium in airborne dust by micellar electrokinetic chromatography, J CHROMAT A, 850(1-2), 1999, pp. 363-368
The separation of diacetylacetonato-beryllium [Be(acac)(2)] from acetylacet
one was achieved with micellar electrokinetic chromatography (MEKC) followe
d by subsequent beryllium analysis carried out using capillary electrophore
sis, Analysis using a separation and absorption detector, with a 50 mu m ca
pillary cell, could detect approximately 1000 ppb of beryllium in the final
sample. Be(acac)(2) is a promising reagent for absorption spectrophotometr
y, because its molar absorption coefficient, (32 000 1 mol(-1) cm(-1)) is v
ery large. As the complex and acetylacetone have a similar absorption wavel
ength, the excess free ligand must removed from the sample to be measured.
Acetylacetone is a weak acid with keto-enol tautomerism in aqueous solution
. Acetylacetone and neutral Be(acac)(2) should be separated with capillary
zone electrophoresis (CZE) using a neutral or basic buffer solution as the
mobile phase. Although the pH and temperature of the mobile phase were opti
mized, separation with CZE was interfered with by a portion of acetylaceton
e. This interfering portion seems to be a neutral keto-form with the same m
igration time as Be(acac)(2). As a neutral species separation method, MEKC
with sodium dodecyl sulfate was tried and the separation was completed. The
optimum pH value and buffer temperature are pH 7.8 and 15 degrees C, respe
ctively. (C) 1999 Elsevier Science B.V. All rights reserved.