CE was coupled to inductively coupled plasma MS (ICP-MS) and ESI-MS to identify and quantify the arsenic species arsenobetaine (AsB), arsenite (As-III), arsenate (Asv), and dimethylarsinic acid (DMA). A GC-flame ionization detector (FID)-based German standard method and ICP-MS were used for validation of the data obtained for arsenobetaine and total arsenic, respectively. LODs obtained with the CE-ESI-TOF-MS method were 1.0 X 10(-7) M for AsB, 5.0 x 10(-7) M for DMA, and 1.0 x 10(-6) M for As-III, and As-V. For the CE-ICP-MS method, LODs were 8.5 x 10(-8) M for AsB, 9.5 x 10(-8) M for DMA, 9.3 x 10(-8) M for As-III, and 6.2 x 10(-8) M for As-V. While CE-ICP-MS provided high sensitivity and better reproducibility for quantitative measurements, CE-ESI-MS with a TOF mass analyzer proved to be valuable for species identification. With this setup, fish samples were prepared and analyzed and the obtained data were successfully validated with the independent methods.