Abstract: The invention provides a method and apparatus for determining the complex impedance of an electrical component. The method comprises the steps of applying an input signal to the component comprising a plurality of discrete frequencies simultaneously, and determining the complex impedance of the component at each of the frequencies using a discrete demodulation technique on two complex impedance related parameters at each of the discrete frequencies. This method is particularly useful in electrically noisy environments and can be used to determine the impedance and equivalent circuit parameters for a battery. It can also be applied to battery system interconnects to enable battery system currents to be determined.

Abstract: Adsorbents composed of a polysaccharide support which is suitable for chromatography and is preferably based on agarose which has undergone a chemical reaction with the glycidyl ethers of nonionic polyoxyethylene detergents of the type HO--(CH.sub.2 CH.sub.2 O).sub.n --O--R to give a compound of the formula I ##STR1## where n is an integer from 2 to 30 andR is an alkyl radical having 4-20 or a phenyl radical or a phenylalkyl radical, where the alkyl radical has 1-16 carbon atoms, to a process for their preparation and to their use for removing lipoproteins from human or animal body fluids are described.

Abstract: The invention relates to a process for the purification of streptolysin O (SLO) by means of chromatography and to the use of streptolysin.