Determination of thiocyanate in plasma and saliva without deproteinisation and its validation as a smoking parameter.
A simple photometric procedure was developed for the determination of thiocyanate (SCN-) in plasma and saliva without deproteinisation or dialysis. Fe(III) ions form a red coloured complex with SCN- with a maximum absorbance at 460 nm. Mercury(II) nitrate is used to run a sample blank. A manual and an automated version (COBAS BIO) of the method is described. The method is linear up to 5000 mumol/l SCN-. The CV of the between-run precision is 2.8-8% for the manual and 2.6-6.6% for the automated method. The SCN- plasma concentration was 21-134 mumol/l in nonsmokers and 44-260 mumol/l in smokers. In mixed saliva, the concentration is much higher than in plasma: 1.57-5.5 mumol/l in smokers and 0.79-3.9 mumol/l in nonsmokers. Plasma, but not oral fluid SCN-, is a valuable parameter for studying smoking habits in population surveys. However, its use is limited. In our experience only heavy smokers can be distinguished from nonsmokers.
Chemisches Zentrallabor der Universitätskliniken, Inselspital Bern.
P
P
Degiampietro
E
E
Peheim
D
D
Drew
H
H
Graf
J P
JP
Colombo
D005260:Female; D006801:Humans; D007202:Indicators and Reagents; D008297:Male; D010306:Parotid Gland / Q000378:metabolism; D010783:Photometry; D012463:Saliva / Q000032:analysis*; D012907:Smoking / Q000378:metabolism*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013861:Thiocyanates / Q000032:analysis* / Q000097:blood
D007202:Indicators and Reagents; D013861:Thiocyanates