APRIL, 1967 THE ANALYST Vol. 92, No. 1093 Heterocyclic Azo Dyestuffs in Analytical Chemistry A Review* BY R. G. ANDERSON AND G. NICKLESS (School of Chemistry, The University, Byisto1 8) SUMMARY OF CONTENTS General introduction and scope 1-( 2-Pyridylazo)-2-naphthol General properties Applications as a complexometr