A Validated Reverse Phase HPLC Analytical Method for Quantitation of Glycoalkaloids in Solanum lycocarpum and Its Extracts

Table 1

Combination of factors to assess the robustness of method.

Factors	Nominal			Variation
Extraction time	A, 2.0 h			a, 1.5 h
Sample size	B, 250 mg			b, 225 mg
Particle size	C, 35 mesh			c, 40 mesh
Extraction temperature	D, 30°C			d, 40°C
Stirring	E, 120 rpm			e, 150 rpm
Extraction volume	F, 20.0 mL			f, 20.5 mL
	Factors level
Combination	1	2	3	4	5	6	7	8
Experiments
A or a	A	A	A	A	a	a	a	a
B or b	B	B	b	b	B	B	b	b
C or c	C	c	C	c	C	c	C	c
D or d	D	D	d	d	d	d	D	D
E or e	E	e	E	e	e	E	e	E
F or f	F	f	f	F	F	f	f	F
Results	s	t	u	v	w	x	y	z

(s) Nominal conditions of method. Variables: (t) particle size, stirring, and extraction volume; (u) sample size, extraction temperature, and extraction volume; (v) sample size, particle size, extraction temperature, and stirring; (w) extraction time, extraction temperature, and stirring; (x) extraction time, particle size, extraction temperature, and extraction volume; (y) extraction time, sample size, stirring, and extraction volume; (z) extraction time, sample size, and particle size.