FAST TIME-RESOLVED MAGNETIC OPTICAL-ROTATORY DISPERSION MEASUREMENTS - 1 - MUELLER ANALYSIS OF OPTICAL AND PHOTOSELECTION-INDUCED ARTIFACTS

A simple and sensitive near-null technique for multichannel nanosecond time-resolved magnetic optical rotatory dispersion measurements is in troduced with a theoretical analysis describing the basis of the techn ique and the effects of optical imperfections, photoselection-induced linear dichroism and birefringence, and the Faraday rotation of the so lvent and cell windows. This treatment identifies a potential artifact in photolyzed samples that is associated with the coupling of photose lection-induced linear dichroism with the solvent-cell Faraday rotatio n. Excitation geometries that minimize this problem are described. Exp erimental applications of the technique to the ligand rebinding reacti on of myoglobin-CO after ligand photolysis are presented in the follow ing article.