Abstract
We report on a quick and simple test based on enzyme inhibition for the detection of mercury and copper using free acid urease coupled to an optical sensor system. Lipophilized Nile Blue was incorporated in plasticized poly(vinyl chloride) (PVC) to produce an ammonium-sensitive layer with a thickness of around 4 μm. The layer was fixed on one side of a disposable cuvette. A solution of buffer, enzyme and heavy metals was placed into the thermostated cell. Enzymatic hydrolysis was started upon addition of urea and the formation of ammonium was monitored. Mercury and copper were the strongest inhibitors; for this reason the inhibitory efficiency of these metals was examined in citrate, acetate and trismaleate buffers. The cuvette test was most sensitive and selective for mercury in a citrate buffer. The limit of detection for mercury(II) ions was as low as 1 μg/L. Copper ions do not interfere because of complexation by citrate. The inhibitory effects of metal combinations on the activity of acid urease and the effects of optimum pH of the enzyme and the transducer on the dynamic range of the cuvette test are presented.
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References
K. R. Rogers,Biosens. Bioelectronics 1995,10, 533.
J. Wang, L. H. Wu, L. Anges,Anal. Chem. 1991,63, 2993.
K. Cammann,Sens. Actuators 1992,B6, 19.
R. Kalvoda,Electroanalysis 1990,2, 341.
C. Dumschat, H. Müller, K. Stein, G. Schwedt,Anal. Chim Acta 1991,252, 7–9.
A. Zürn, H. Müller,Fresenius'J. Anal. Chem. 1993,346, 589.
C. Preininger, O. S. Wolfbeis,Anal. Chem. 1994,66, 1841.
K. Riedel, R. Renneberg, M. Kühn, F. SchellerAppl. Microbiol. Biotechnol. 1988,28, 316–318.
I. Karube,Biotechnol. Bioeng. 1977,19, 1535.
U. Obst, K. Resch, T. Feuerstein,Vom Wasser 1985,65, 119.
W. H. R. Shaw,J. Am. Chem. Soc. 1961,83, 3184.
C. Preininger, O. S. Wolfbeis,Biosens. Bioelectronics 1996,11, 981.
I. Satoh,J. Flow Injection Anal. 1991,8, 111.
L. Ögren, G. Johansson,Anal. Chim. Acta 1978,96, 1.
R. T. Andres, R. Narayanaswamy,Analyst 1995,120, 1549.
D. W. Bryce, J. M. Fernandez-Romero, M. D. Luque de Castro,Anal. Letters 1994,27, 867.
A. Amine, C. Cremisini, G. Palleschi,Mikrochim. Acta 1995,121, 183.
J.-C. Gayet, A. Haouz, A. Geloso-Meyer, C. Burstein,Biosens. Bioelectronics 1993,8, 177.
T. Danzer, G. Schwedt,Anal Chim. Acta 1996,318, 275.
F. Krebs,Gewässerschutz, Wasser, Abwasser 1983,63, 173.
G. Schwedt, D.-O. Waldheim, K.-D. Neumann, K. Stein,Fresenius'J. Anal. Chem. 1993,346, 659.
Ciba GeigyWissenschaftliche Tabellen 1979,Vol. 2, 8th Edn.
W. E. Morf, K. Seiler, B. Rusterholz, W. Simon,Anal. Chem. 1990,62, 738.
K. M. Harmon, C. Niemann,J. Biol. Chem. 1949,177, 601–605.
K. Oehlschlager, R. Huttle, Wolf, GSOThermochin. Acta 1998,310, 185–189.
D. A. Skoog, D. M. West, F. J. Holler,Fundamentals of Analytical Chemistry, 6th Edn. Saunders College Publishing 1991
R. Pribil,Applied Complexometry. Pergamon, New York.
E. Merian,Metals and Their Compounds in the Environment, 1991, VCH, Weinheim, Germany
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Preininger, C. The enzymatic determination of mercury and copper using acid urease. The effects of buffers. Mikrochim Acta 130, 209–214 (1999). https://doi.org/10.1007/BF01244930
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DOI: https://doi.org/10.1007/BF01244930