Table 4.

Mean extraction efficiencies, matrix effects and analyte stability at room temperature, 4 and −20°C for cannabinoids in human urine.

Analyte	Extraction efficiency (%, N=12)		Matrix effect (% of signal suppressed, N=12)		RT 21h (% difference, N=3)		4°C 72h (% difference, N=3)		3 freeze-thaw cycles (% difference, N=3)
	Low	High	Low	High	Low	High	Low	High	Low	High
THCVCOOH	81.5	73.6	9.2	9.1	−1.7	2.0	−1.3	3.1	−6.7	0.0
THCCOOH-gluc	63.4	57.9	0.3	10.2	−20.3	−20.3	2.8	2.5	3.7	3.1
THC-gluc	72.0	67.6	32.0	32.5	−15.4	−4.1	−3.0	−1.5	−0.1	0.0
THCCOOH	73.9	69.4	0.0	9.0	1.3	5.1	6.2	2.8	−1.3	−1.1
THCAA	42.4	42.5	−10.0	−6.0	−55.4	−57.1	−15.8	5.2	3.7	−7.7
11-OH-THC	73.6	71.1	7.2	11.3	−4.2	−5.3	−3.1	2.9	3.5	−2.2
THCV	68.9	65.8	1.9	9.0	−52.7	−41.8	−14.9	−2.5	−10.6	−10.1
CBD	73.6	68.7	2.0	11.5	−59.4	−56.6	−2.0	−8.9	0.7	−9.4
CBG	69.5	66.9	1.4	6.5	−62.6	−62.7	−9.3	−14.7	−10.1	−14.7
CBN	54.7	52.3	1.1	10.7	−55.2	−57.1	−0.8	−5.4	−3.9	−6.9
THC	58.4	55.7	0.6	6.4	−55.7	−58.3	−16.4	−8.8	−5.0	−7.2