Effect of extraction condition of SPE

Matrix effect/Ion suppression (%)
Ion Source	Extraction method	QC samples
Ion Source	Extraction method	LQC	MQC	HQC
ESI	Solid Phase Extraction	7.8	6.7	9.4
	Liquid Liquid Extraction	17.1	18.6	24.4
	Protein Precipitation	22.5	19.2	28.0
APCI	Solid Phase Extraction	4.6	5.2	5.9
	Liquid Liquid Extraction	14.1	16.8	20.2
	Protein Precipitation	20.8	17.4	22.0

Table 5: Ion suppression of bosentan across all QC levels after extraction with different techniques and analyzed on different ion source in MS.