
Combined analysis of N′-nitrosonornicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol in the urine of cigarette smokers and e-cigarette users
Keywords: NNN, N′-nitrosonornicotine; NNAL, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol; NNK, 4- (methylnitrosamino)-1-(3-pyridyl)-1-butanone; SLE, supported liquid extraction; SPE, solid-phase extractionCombined analysis; N′-Nitrosonornicotine; NNAL; 4-(Methylni