Determination of Tobramycin in M₉ Medium by LC-MS/MS: Signal Enhancement by Trichloroacetic Acid

Table 4

Stability of TBM.

Conditions		% remained	RSD (%)	n
In autosampler vial, 21–25°C, 3 days
	300 ng/mL	107	3.5	3
	20000 ng/mL	105	2.4	3
In M9, 21–25°C, 5 days
	300 ng/mL	104	8.1	3
	20000 ng/mL	99.2	3.6	3
3 freeze-thaw cycles
	300 ng/mL	99.4	5.0	3
	20000 ng/mL	99.8	2.4	3
In M9 medium, 6 days, −70°C
	300 ng/mL	93.8	3.3	3
	20000 ng/mL	101	3.0	3
IS (5000 ng/mL) in water		102.9	0.74	3
	24 hr, 21–25°C	74.2	3.4	3
	5 days, 21–25°C	79.5	1.7	4