1125
Anal. Chem. 1087, 5 9 , 1125-1129
Table V. Apparent Association Constants of the Complexell Formed by Calcein Blue and Methyl Calcein Blue with Divalent Transition-Metal Ions
methyl Ln(II1)
calcein blue
calcein blue
Mn
28 400 20 550 24 060 21 680 27 320 12 685
1690 3 750 a 380 11980 18 920 4 650
Fe co
Ni CU Zn
Cu(I1) and the other with 5% Cu(I1). The response of the calcein blue reagent to these solutions was obtained, and the Stern-Volmer quenching parameters thus measured are collected in Table IV. It was concluded that the addition of 2% Cu(I1) yielded only a 0.4% error in computed Gd(II1) concentrations, while the addition of 5% Cu(I1) yielded only a 1.3% error. Apparent association constants for the transition-metal complexes with calcein blue and methyl calcein blue were computed from the quenching data by using the same analysis
as previously described. These constants are found in Table V, and comparison with analogous iminodiacetate and amino acid complexes (9) indicates that the dye complexes are less stable than those of the parent chelating group. This observation implies that the steric bulk of the umbelliferone group interferes with the complexation process, as had been inferred for the lanthanide-dye complexes. LITERATURE CITED Howell, J. A.; Hargis, L. G. Anal. Chem. 1988, 58, 108. Wehry. E. L. Anal. Chem. 1988, 58 13. Yoshida, K.; Haraguchl, H. Anal. Chem. 1904, 5 6 , 2580. Wllklns, D. H. Talanta 1960, 4 , 182. Escarrllla, A. M. Talanta 1988, 73,363. Elsheimer, H. N . Talanta 1867, 14, 97. Hems, R. V.; Klrkbrlght, G. F.; West, T. S. Anal. Chem. 1970, 4 2 , 784. Wilkins, D. H. Talanta 1980, 23, 309. Martell, A. E.; Smith, R. M. Critical Stability Constants; Plenum: New York, 1974, Vol. 1. Boaz, H.; Rollefson, G. K. J. Am. Chern. Soc. 1950, 72, 3435. Keizer, J. J . Am. Chem. Soc. 1983, 705,1494.
RECEIVED for review September 2, 1986. Accepted January 9, 1987.
Development of Sensitive Multiwavelength Fluorescence Detector System for High-Performance Liquid Chromatography Kiyoshi Tanabe,' Mark Glick, Benjamin Smith, Edward Voigtman, and James D. Winefordner*
Department of Chemistry, University of Florida, Gainesville, Florida 32611
A sensitive, multiwavelength fluorescence detector system for hlgh-performance llquld chromatography (HPLC), which slmuttaneously monitors four fluorescence wavelengths on four Interference fllter-photmuttlpller tube detector channels, has been developed to reallre both hlgh sensltlvlty and hlgh selectlvlty. Performance of the system has been estimated by uslng several polycycllc aromatlc hydrocarbons ( PAHs). Detectlon llmlts In the picogram range and llnearlty of callbratlon curves over 104-106 were obtained for most PAHs. Repoduclbillty was 0.7-5.9 % (relatlve standard devlatlon, N = 7) and stablttty was
