Table 4 Robustness data of HE

Robustness	Time (h)	Peak area	Mean±SD1)	RSD (%)2)
	Initial	3403
		3392	3,401±8.6	0.3
		3409
	10	3392
		3394	3,396±4.7	0.1
		3401
	20	3390
		3391	3,395±8.4	0.2
		3405
	24	3407
		3399	3,400±6.1	0.2
		3395

Robustness data of HE
Relative standard deviation.