Committee on Enzymes IFCC methods for the measurement of catalytic concentration enzymes Part 7. IFCC method for creatine kinase creatine N-phosphotransferase, EC 2.7.3.2). IFCC Recommendation

stoichiometry of the air-acetylene flames between the two portions of the experiment.Interferences in the nitrous oxide-acetylene flames were measured at three stoichiometries: lean, medium, and rich. The curves varied considerably from each other, but not in any identifiable pattern; one stoichiometry did not appear to give "better" results than another. The data in the Figures 2-5 were taken from the medium flame. CONCLUSIONSThe primary conclusion emerging from these experiments is that use of the air-acetylene flame burning on the single slot, flat-top burner produces the fewest interferences when determining copper, manganese, and nickel in acid media. Both the air-acetylene flame burning on a 3-slot head and the nitrous oxide-acetylene flame showed a greater tendency to exhibit interference effects, suggesting that these flames should be chosen with caution. For chromium the choice is not so clear. Both air-acetylene and nitrous oxide-acetylene flames produced roughly equivalent sensitivities and acid interferences. In this case the choice would be dependent on the presence of other possible interferences.The interferences from hydrochloric and nitric acids were smallest indicating that these acids should be used if there is a choice of dissolution methods. However, if high accuracy is required, and the acid medium is other than dilute, standards should be made up in approximately matching concentrations of the same acid or acids.Finally, it is clear that the design of the burner system has an important influence on analytical interferences, even within the general category of premix burners. The interferences found in this work are far smaller and less important than those reported in Reference I , in which a different premix burner system was employed.An atomic absorption flame spectrometer employing chopper modulated continuum radiation and wavelength modulation of radiation transmitted through the flame cell is described. The instrumental system does not respond either to Rayleigh scattering or to molecular absorption and emission processes occurring within theflamegases. Limits of detection of the order of 0.1 bg/ml and analytical curves linear over at least three orders of magnitude in concentration for Ag, Ca, Cd, Cr, Cu, Fe, Mg, and Ni are obtained. Expressions are derived to predict the response of the instrumental system to variation in experimental parameters and are verified experimentally.

tempt to review briefly, the fundamental aspects, the instrumental requirements, and the analytical uses of atomic fluorescence spectrometry.

A novel design for a monochromatorless atomic fluorescence spectrometer is presented. The instrument was used to measure the atomic fluorescence of Cd, Hg, and Zn. Analytical curves obtained agreed with theoretical predictions. Limits of detection and scatter experiments demonstrated the sensitivity and selectivity of the instrument.

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