Table 4. Inter-laboratory reproducibility results of recovery for Bixin and Norbixin

Compound	Sample	Fortified concentration (mg/L)	Recovery±SD (%)			Average±SD (%)	RSD (%)
			Lab. A	Lab. B	Lab. C
Bixin	Cheese	2	92.97±1.79	97.99±0.17	102.52±1.50	96.66±4.04	4.18
		5	94.89±3.27	96.26±1.72	103.39±1.53	96.16±3.51	3.65
		10	95.47±2.80	97.94±0.44	103.17±1.52	97.73±2.79	2.85
Norbixin	Cheese	2	93.79±2.72	94.67±1.94	101.53±0.60	97.83±4.30	4.39
		5	94.20±2.09	94.00±2.30	100.27±1.23	98.18±4.43	4.51
		10	95.62±2.60	96.84±0.56	100.73±1.64	98.86±3.76	3.81

RSD, relative SD.