Compound	AsA		Total AsA
	Test (ml)	Blank (ml)	Test (ml)	Blank (ml)
0.2 M K-buffer pH 7.4	0.25	0.25	0.25	0.25
10 mM DTT	–	–	0.05	0.05
Incubation: 10 min at 25 °C
0.5 % (w/v) NEM	–	–	0.05	0.05
ddH2O	0.1	0.1	–	–
10 % (w/v) TCA	0.2	0.2	0.2	0.2
44 % (v/v) H3PO4	0.2	0.2	0.2	0.2
4 % (w/v) 2,2′-dipyridyl	0.2	0.2	0.2	0.2
3 % (w/v) FeCl3	0.2	0.2	0.2	0.2
Incubation: 40 min at 42 °C