19.若欲得到promethazine製劑中不純物的分子式,利用下列何者最合適?
(A)氣相層析-四極柱質譜儀(gas chromatography-quadrupole mass spectrometry)
(B)液相層析-四極柱質譜儀(liquid chromatography-quadrupole mass spectrometry)
(C)液相層析-離子阱質譜儀(liquid chromatography-ion trap mass spectrometry)
(D)液相層析-傅立葉轉換質譜儀(liquid chromatography-fourier transform mass spectrometry)