Table 3.

Analysis of variance of the 7 main effects and 21 interaction effects affecting iron-catechol complexation, significant factors and corresponding p-values are indicated in bold (R² = 0.76 and R²_adj = 0.70).

Factor	Sum of Squares	Mean Square	F Value	p-value	Contribution (%)
A (type of iron salt)	937383	468691	115	6.68 × 10−40	19
B (pH)	811126	405563	99	1.42 × 10−35	16
C (Temperature)	509469	254735	62	3.11 × 10−24	10
D (Ionic strength)	16304	8152	2	0.14	0
E (Concentration iron)	100814	50407	12	6.27 × 10−6	2
F (Ratio [Fe]:[Cat])	869	434	0	0.90	0
G (MSG)	59483	29742	7	7.78 × 10−4	1
A × B	780182	195045	48	1.15 × 10−32	16
A × C	90012	22503	6	2.50 × 10−4	2
A × D	73998	18500	5	1.36 × 10−3	1
A × E	442251	110563	27	7.57 × 10−20	9
A × F	2235	559	0	0.97	0
A × G	9240	2310	1	0.69	0
B × C	357090	89272	22	2.66 × 10−16	7
B × D	32866	8216	2	0.09	1
B × E	7930	1982	0	0.75	0
B × F	11954	2989	1	0.57	0
B × G	26167	6542	2	0.17	1
C × D	5424	1356	0	0.86	0
C × E	193111	48278	12	4.41 × 10−9	4
C × F	33035	8259	2	0.09	1
C × G	121354	30338	7	8.83 × 10−6	2
D × E	8845	2211	1	0.70	0
D × F	157640	39410	10	1.86 × 10−7	3
D × G	40674	10169	2	0.04	1
E × F	10606	2651	1	0.63	0
E × G	81992	20498	5	5.86 × 10−4	2
F × G	16030	4008	1	0.42	0