[Retracted] A Simple HPLC-UV Method for the Determination of Glutathione in PC-12 Cells

Table 4

Summary of robustness studies.

Experimental conditions	Variation	RT (min) of; Peaks 1, 2, and 3	Combined peak areas	Tailing factor
Change in gradient time (min)	18	6.22, 10.22 & 13.25	58992	1.20
	20 (nominal)	7.52, 11.02 & 14.18	55002	1.20
	22	8.29, 11.89 & 14.98	54999	1.21
Buffer pH	2.48	7.51, 11.12 & 14.21	55022	1.22
	2.5 (nominal)	7.52, 11.02 & 14.19	55002	1.20
	2.52	7.52, 11.08, & 14.17	55462	1.22
Wavelength (nm)	282	7.50, 11.06 & 14.28	56734	1.23
	280 (nominal)	7.52, 11.02, 14.35	55002	1.20
	278	7.55, 11.07, 14.44	53878	1.20
Flow rate (mL/min)	0.6	10.35, 14.22 & 17.85	55474	1.18
	0.8 (nominal)	7.52, 11.02 & 14.44	55002	1.20
	1.0	5.6, 8.62 & 11.28	54878	1.23
Injection volume (L)	48	7.49, 10.99 & 14.84	53998	1.21
	50 (nominal)	7.52, 11.02 & 14.47	55002	1.20
	52	7.50, 11.01 & 14.25	56878	1.21
Column type	Zorbax C8	7.66, 11.32 & 14.24	52345	1.25
	Eclipse XDB C8	7.52, 11.02 & 14.44	55002	1.20
	Zorbax C18	7.92, 11.92 & 14.65	60233	1.49

Note: RT: retention time; Peak 1 is 2-nitro-5-mercapto-benzoic acid, Peak 2 is glutathione dimer, and Peak 3 is Ellman’s reagent.