Table 1.

Regression equations for the rate of ^.OH production as a function of concentration of individual and mixed redox-active species.

Equation Number	Compound(s)	Regressiona	R2	Concentration Range (nM)b	Number of Data Points
Individual compounds
Eq. 1	Cu(II)	ROH = 0.0383×Ln([Cu]) + 0.009	0.95	0.8c – 10,000	14
Eq. 2	Fe(II)	ROH = (−3.13×10−8)[Fe]2 + (6.86×10−4)[Fe]	0.995	0 – 10,000	13
Eq. 3	1,2-NQN	ROH = 0.486×(1-exp(−0.0191*[1,2-NQN]))	0.997	0 – 500	7
Eq. 4	1,4-NQN	ROH = (2.59×10−4) ×[1,4-NQN]	0.94	0 – 500	4
Eq. 5	PQN	ROH = 0.312×(1-exp(−0.0053×[PQN]))	0.999	0 – 500	4
Mixtures of Fe, Cu and/or quinones
Eq. 6	Mixture	ROH = 0.198×(RHOOH,Cu + 1.56×RHOOH,Q) + 8.64E-04×[Fe(II)]	0.993	n/a	20
	Where:	RHOOH,Cu is the rate of HOOH production from Cu in μM/hrd = 0.524×ln([Cu]) – 0.615
		RHOOH,Q is the sum of rates of HOOH from quinones in μM/hrd = 0.050×[1,2-NQN]+0.0052×[PQN]+0.0024×[1,4-NQN]

^aR_OH is the rate of ^.OH production in μM/hr and [X] is the concentration of redox-active chemical species in nM.

^bRegression equations may not be valid outside of the concentration ranges measured.

^cThe Cu(II) regression equation goes to zero at 0.8 nM of Cu(II). ^.OH values should be assumed to be zero at copper concentrations below this.

^dThe rates of HOOH production from Cu and quinones in Eq. 6 are regression equations from individual species measured previously²².