Table 2.

Sample characteristics.

Acids	Formula	Range (pH)	Mean	n (calibration)	n (prediction)
Citric	C6H8O7	1.88–4.32	2.88	50	50
Tartaric	C4H6O6	2.06–4.52	3.12	50	50
Malic	C4H6O5	1.99–4.44	3.17	50	50
Oxalic	C2H2O4	1.95–4.35	3.16	50	50