| http://www.w3.org/ns/prov#value | - Suitable cations Ay+ are those of metals, especially alkali or alkaline earth metals, such as sodium, potassium, magnesium or calcium, ammonium, substituted phosphonium of formula ##STR2## and substituted ammonium of formula ##STR3## where R1, R2, R3 and R4, which may be the same or different, represent alkyl, alkenyl, aryl, aralkyl, cycloalkyl, or cycloalkylalkyl groups which may be substituted o
|
