Acetone as solvent in flame-photometric determination of lithium in serum.
Abstract The effect of some water miscible organic solvents on the flame photometric emission of Li is discussed. A simple procedure is described with acetone as diluting solution giving a ten to twenty fold increase in sensitivity.
Micro flame photometric determination of sodium, potassium, and calcium in serum with organic solvents.
The effect of organic solvents on the flame photometric emission of certain elements in petroleum products has been reported (1). Propanol, hutanol, and acetone have been used in the flame photometric determination of sodium and potassium in serum, but these organic solvents were not used routinely, “as it was feared that complications might arise in practice owing to their volatility and to the restricted solubility of NaCl and KC1 in some solvents” (2). Apparently no extensive investigation has been made of the effect of organic solvents on the emission spectra of the cations of blood serum. We have investigated the use of organic solvents to extend the sensitivity of the flame photometer in the direct determination of sodium, potassium, and calcium, and to make practical the analyses of extremely small biological specimens. Our investigation of the effect of organic solvents on the emission spectra of sodium and potassium (3) indicated that, of the solvents studied, acetone produced the greatest enhancement of emission spectra. Less enhancement was produced by methanol, ethanol, propanol, and isopropanol in the order named. Acetone increased the spectral emission of sodium 17-fold in relative per cent transmittance and potassium 13-fold as compared with the aqueous solvent. This investigation also indicated that bovine albumin* had no effect on sodium and potassium spectra. Further study of organic solvents has been made to test their enhancement effect on the emission spectra of sodium, potassium, and especially of calcium. The use of an aqueous solvent for the direct microphotometric determination of sodium, potassium, and calcium in a single biological specimen has been reported (4).
Continuity, Legitimacy, and Agricultural Development: Conclusions
This chapter aims at bringing together the principal conclusions of the volume, emphasising some particular aspects and questions. Policy continuity in relation to the late 1980s was rightly defined by the Aylwin government policymakers as an essential instrument for further agricultural growth. But in a democratic environment the Aylwin policies, in part precisely because of their strong element of continuity, could be implemented only if they were perceived as legitimate by the majority of the rural population, and by the poor in particular. This means that substantial improvements in agricultural income distribution, and in the quantity and quality of the social services provided to the rural poor, were unavoidable. In order to achieve legitimacy it was, and is, necessary to introduce changes. A lucid, creative combination of continuity and change was the only guarantee of success for the Aylwin policies, and for those of future democratic administrations. Continuity and legitimacy are the fundamental pillars for democratic agricultural development.