nitric oxide ( no ) has a number of important functions in biological systems and may play a role in the toxicity of mineral fibers . 
 we investigated whether no might be present on the surface of mineral fibers and if crocidolite could adsorb no from no gas or cigarette smoke . 
 no was determined with a new gas chromatography - ultraviolet spectrophotometric technique after thermal desorption from the fiber surface and injection in a gas flow cell . 
 no was found in different amounts on chrysotile b , crocidolite , amosite , and silicon carbide whiskers . there was a strong correlation between the amount of no and the specific surface area of these fibers ( r = 0.98 ) . 
 no could not be demonstrated on rockwool fibers [ man - made vitreous fiber(s ) ( mmvf)21 and mmvf22 ] or silicon nitride whiskers . 
 no on crocidolite , amosite , and silicon carbide whiskers was readily desorbed from the fibers at increased temperature , while no on chrysotile b seemed to be more firmly adsorbed to the fiber and required a longer period of time to be desorbed . 
 the amount of no bound to crocidolite increased from 34 micrograms / g fiber to 85 and 474 micrograms / g after exposing the fibers to cigarette smoke and no gas , respectively . 
 these findings indicate that a ) no adsorbs to fiber surfaces , b ) some fibers adsorb more no than others , c ) some fibers adsorb no more strongly than others , and d ) the amounts of no on fibers may be increased after exposure of the fiber to cigarette smoke or other sources of no . 
 the biological significance of no on mineral fibers remains to be investigated.imagesfigure 3 .