Table 1.

Extinction coefficients determined or employed.

Species	pH	Wavelengths(nm)	E(mM− 1 cm− 1)
O (absolute spectrum)	8.75	423–460	133.3
		598–630	13.75
		825–(750 + 900)/2	0.74
CuA red minus oxidised	7.4	825–(750 + 900)/2	0.60
F minus O	8.75	579–630	(5.5)*
		606–630	1.05
		436–412	54.3
P minus O	8.75	606–630	(11.0)*
		579–630	2.15
		437–412	49.8
CO reduced minus reduced	8.75	590–606	9.2
Haem a3 & CuB reduced minus oxidised	8.75	605–630	3.5
Haem a reduced minus oxidised	8.75	605–630	23.5

Determined in this paper apart from: * Morgan and Wikstrom [40].