We report a possible means to selectively isolate C-13 from carbon monoxide (CO) exploiting multiphoton dissociation near 199 nm. At lambda = 199.363 nm we observed mass spectra with greater than 95% C-13(+) ions produced from CO with normal isotopic abundance. The technique of velocity map ion imaging was applied to explore this effect. The complete mechanism for the C-13(+) detection reads as follows: CO(X(1)Sigma(+)) + hv --> CO(a(3)Pi(1)), CO(a(3)Pi(1)) + hv --> C(D-1(2)) + O(P-3(o)), C(D-1(2)) + hv --> C(P-3(1)), C(P-3(1)) + hv C+ + e(-). We also report the molecular constants for the CO h(3)Sigma(+), state for (CO)-C-12 (v(00) = 100 385(.5) cm (1), B = 1.97, cm(-1)). (C) 2002 Published by Elsevier Science B.V.