To perform efficient analytical investigation combined with low
analytical run time in all samples types (tape strips, skin and receptor
fluid), different parameters of the LC-MS method were optimized
(spray voltage, capillary temperature and nebulizer pressure) (data
not shown). Each chromatographic run was completed within
6 min, and A-A-A had a retention time about 2.43 0.12 min. A
typical LC-MS spectrum is presented in Fig. 2 below.
Three external calibrations of A-A-A (0.1–20 mg L