Precise measurement of nitric oxide (NO) is of great importance to understand the function of NO in liver and the mechanism of liver injury. 8-(3', 4'-Diamino phenyl)3,5-(2-hydroxyphenyl)-dimethylene pyrrole (BOPB), a fluorescent probe in the red region (>600 nm) newly developed in our group, has good photostability and excitation/emission wavelength of 622/643 nm matching well with commercial 635 nm semiconductor laser of CE-LIF detection. Therefore, BOPB was used in CE-LIF for the determination of NO in mice liver. Both derivatization and separation conditions were optimized. Derivatization reaction of BOPB and NO was carried out in pH 7.4 PBS buffer at 35 degrees C for 12 min and the separation of NO derivative of BOPB (BOPB-T) was achieved within 7.0 min in pH 9.0 running buffer containing 15 mM H3BO3-NaOH and 15 mM SDS. Good linearity was found in the range of 1.0 x 10(-9)-5.0 x 10(-7) M with the LOD of 0.02 nM. The proposed method was applied to the analysis of NO in real samples, and NO concentration was obviously increased in acute liver injury of mice. Compared to existing derivatization-based CE-LIF methods for NO, this method has lower LOD and less background interference owing to detection wavelength of BOPB in the red region.