Separation and determination of mercury from nail and hair in petrochemical workers based on silver carbon nanotubes by microwave-assisted headspace sorbent trap

In this work, the occupational analytical chemistry was developed for determination of chronic exposure of mercury in nail and hair in petrochemical workers (age: 30-50, men). by experimental procedure, 100 mg of hair and nail of workers was prepared by washing / grinding and then the powder was dried in oven for 20 min at 95˚c. 20 mg of hair or nail samples added to reagents (hno3/h2o2; 5:1) in polyethylene tube (pet) of microwave digestion and the mercury in resulting solution was removed with silver nanoparticles pasted on multi-walled carbon nanotubes (ag-mwcnts) which were placed in head space of separator. after microwave digestion for 25 min, the mercury vapor was removed by ag-mwcnts as the headspace sorbent trap (hsst) under hood conditions. finally, the mercury in sorbent was online determined by cold vapor atomic absorption spectrometry (cv-aas) after heat process at 250˚c in presence of ar gas. the capacity adsorptions of ag- mwcnts and mwcnts for mercury removal from air were obtained 205.4 mg g^-1 and 63.7 mg g^-1, respectively. the mean of mercury in nail and hair in workers and healthy peoples was achieved (15.2±3.7 μg g^-1; 11.6± 2.6 μg g^-1) and (0.16±0.05 μg g^-1; 0.24± 0.03 μg g^-1), respectively (rsd<5%). the validation of method was done by certified reference material (crm).