A revised method for determination of dialkylphosphate levels in human urine by solid-phase extraction and liquid chromatography with tandem mass spectrometry: application to human urine samples from Japanese children

Table 3 Accuracy, precision, LOD and LOQ data of analytical procedure

	Concentration (μg/L)	n	DMP	DMTP	DEP	DETP
Within-run precision (%RSD)	1	4			10.3	6.4
	2	4	3.1	9.8	10.7	3.4
	5	4	3.1	2.7	3.9	4.5
	10	4	3.6	5.8
	20	4			5.5	3.2
	100	4	6.7	3.6
Mean recovery^a	1	2	95	64	81	101
Mean recovery^a	5	2	100	105	82	93
Between-run precision (%RSD)	1	7	6.9	7.7	9.6	7.6
Between-run precision (%RSD)	10	7	9.0	4.3	7.5	7.8
R ² of calibration line			0.999	0.998	0.997	0.999
LOD (μg/L) (S/N = 3)			0.4	0.4	0.2	0.1
LOQ (μg/L) (S/N = 10)			1.2	1.2	0.6	0.3

n number of observations, RSD relative standard deviation, LOD limit of detection, LOQ limit of quantitation
^aRecovery obtained by adding the standards just before the separation analysis step

ISSN: 1347-4715