Table 1.

Cystine recovery (accuracy), precision and matrix effect measurements obtained after analysis of the spiked cell samples at three different concentrations

Cystine concentration (μmol/L)	Recovery		Intra‐day run precision	Inter‐day run precision	Matrix effect
	Cell extracts ± SD (%)	Whole cells ± SD (%)	CV (%)	CV (%)	± SD (%)
0.25	99.9 ± 11.2	101.7 ± 15.4	13.16	13.24	100.8 ± 10.5
8.0	101.4 ± 13.0	102.9 ± 8.3	7.30	7.42	101.7 ± 4.7
16.0	97.3 ± 7.9	98.7 ± 13.6	4.71	4.69	99.4 ± 2.8

Recovery and matrix effect in ± SD and precision in CV of three independent experiments performed in triplicate.