Spectrophotometric multi-sample determinations for small amounts of hemoglobin were performed using a 96-well microtiter plate based on an oxidative decomposition reaction of the copper(II)-phthalocyanine complex. As a result of examining the optimization of various conditions, the concentration of peroxomonosulfate as an oxidizing agent was 3.6 10 2 M, the pH was 2.0, and the concentration of sodium sulfate as a salt, which was contained in the pH buffer solution, was about 6.5 10 2 M. In the proposed method, the calibration range was 30 258 ng/ml. The detection limits (3 σ) were 16.99 ng/ml, and the relative standard deviation for 96 samples was 3.64 at the midpoint of the calibration range. As a result of examining foreign substances, cobalt(II), iron(III) and albumin had some influence, but other metal ions and organic compounds did not have any effect. The proposed method was successfully applied to the detection of trace amounts of hemoglobin in human serum samples. Moreover, the hemoglobin analysis for 96 samples was possible to be simultaneously performed within about ten minutes, including not only the time spent for the quantitative operation, but also for the measurement time.

1．IntroductionThe recovery of valuable metals from waste is an important process for building a sustainable society. Solvent extraction 1) , coprecipitation 2) , an ion-exchange resins 3) , and solid-phase extraction [4][5][6][7][8] have been commonly used to separate metal ions from aqueous solutions. Among these methods, solvent extraction has been used recently to separate precious metals. However, sometimes harmful organic solvents such as benzene and chloroform are used. Therefore, for the treatment of liquid wastes, it is necessary to reduce the solvent amounts. In recent years, the coprecipitation method has not been used sufficiently because troublesome skill is sometimes required for a precipitate formation and so on. Because the solid-phase extraction method is comparatively simple, it has been widely used. It is considered that a chelating resin 9-11) that immobilizes a certain functional group on a resin or silica is useful for recovering valuable metal ions 12, 13) among the solid phase extractions. High selectivity for the target metal ions is obtained by selecting functional groups such as iminodiacetic acid, a dithiocarbamic acid, and an amidoxime, which are chemically modified on a solid-phase. However, the ability of these chelating resins to collect metals significantly decreases because of liquid wastes in strongly acidic aqueous solutions such as sulfuric acid. Although this method has been beneficial for isolating a metal ion from other types of ions by using only one chelating resin, it is not simple. Fig. 1) forms very stable complexes with several metal ions. In particular, DFB forms a colored complex with Mo, Ti, and V in a strongly acidic solution 14) . These complexes have been known as containing metals coordinated by the two or three hydroxamate functions of the ligand 15,16) . In the previous studies, authors examined DFB characteristics in order to detect V (V) by the modified cellulose paper 14) and in order to concentrate metals by the solvent extraction 17). As results, it was obtained that DFB was useful not only to detect and to concentrate metals but also to collect metals by the solid phase extraction. Compared with the solvent extraction, the solid phase extraction is no use of harmful organic solvent. Also, it is easy to separate and to collect metals by this method. Based on these knowledges, the study of the solid phase extraction with DFB was performed. A DFB which could complex with seven kinds of high-valence metal ions (i.e., Ti (IV) 14) , V (V) 14) , Zr (IV) 17) , Nb (V) 17) , Mo (VI) 14) , Ta (V) 17) , W (VI) 17) ) in a strongly acidic solution, was chemically modif ied on a polymer gel. High-valence metal ions were selectively adsorbed on a new chelate resin in a strongly acidic solution, and were desorbed from the resin using neutral-to-alkaline solutions. In addition, the developed separation and recovery method was examined. It was found that the DFB-modif ied sorbent is very useful for mutual Development of Metal-Isolable Polymer-Gel Sorbent forMutual Separat...