226 



CARBON 



for the solid counts, since this would approach infinite thickness. How- 

 ever, this entire sample could be converted to CO2 for measurement in a 

 250-ml ionization chamber. Under these conditions the ion-chamber 

 method has an actual effectiveness of about 150 times that of the solid- 

 counting methods. 



In summary, then, the gas measurement should be seriously considered 

 for situations where considerable numbers of relatively large samples of 

 very low activity are anticipated. Under other conditions, solid counting 

 appears to be the more convenient. 



Following is a list of commercially available C'^-labeled compounds 

 (C-21). It is expected that any compound for which there is a demand 

 will eventually be obtainable. See reference (C-21) for addresses of 

 suppliers. (See page 71 regarding radiation decomposition.) 



Acetic acid-1-Ci* 



Aectone-l,3-C" 



Acetone-2-Ci^ 



Acetonitrile-2-Ci^ 



Acetophcnone-a-C ^* 



Acetophenone-7-Ci'' 



Acetyl chloride-1-Ci'' 



Acetylcholine bromide (trimethyI-2-acet- 

 oxyethyl-l,2-C '^-ammonium bromide) 



Acetylcholine methyl-C'^ chloride 



Acetylene-C^^ 



Adenine-Ci'' (uniformly labeled) 



Adenine-8-C'^ 



Adenosine diphosphatc-C'^ (uniformly 

 labeled) 



Adenosine-5-phosphoric acid-C^^ (uni- 

 formly labeled) 



Adenosine triphosphate-C'-* (uniformly 

 labeled) 



Adenylic acid-Qi^ (uniformly labeled) 



Adenylic acid A-C^'^ (uniformly labeled) 



Adenylic acid 5-C" (uniformly labeled) 



Adipic acid-l-C" 



Adipic acid-l,6-C" 



DL-Alanine-1-Ci^ 



DL-Alanine-2-C" 



Algae-C" (C. pyrenoidosa, dried) 



Alkanes (Cb-CsO-C" 



Alloxan-2-Ci4 



p-Aminobenzoic acid-carboxyl-C^* 



DL-Aminobutyric acid-l-C" 



DL-Aminobutyric acid-2-Ci^ 



DL-Aminobutyric acid-3-C'* 



DL-a-Aminobutyric acid-l-C^* 



7-Aminobutyric acid-l-C^^ 



M-Amyl alcohol- l-C'' 



Amyl bromide-1-C" 



Aniline-1-C" 



Anthranilic acid-carboxylic-Ci* 



D- Arabinose- 1 -C ' ^ 



D-Arabinose-5-C''' 



L-Arginine-C" (uniformly labeled) 



DL-Aspartic acid-4-C'^ 



L-Aspartic acid-C'' (uniformly labeled) 



8-Azaguanine-2-C''' 



Barbituric acid-2-C" 



Barbituric acid-4,6-C" 



Barium carbide-Ci" 



Barium carbonate-C'' (up to 1 fic in 



each vial) 

 Barium D-gluconate-l-C^^ 

 Benzanthracene-5,6-C''' 

 Benzene-C'' 

 Benzene-l-C^^ 

 Benzoic acid-C^* 

 Benzoic acid-l-C^* 

 Benzoic acid-7-C^* (up to 1 mc in each 



vial) 

 Benzoic acid-carboxyl-C'' 

 Benzyl alcohol-7-C» 

 Bromoacetic acid-l-C'* 

 Bromoacetic acid-2-Ci* 

 Butane-1-C" 

 di-n-Butyl-l-C" adiapate 

 n-Butyl alcohol-l-C»^ 

 n-Butyl aldehyde-1-Ci* 

 n-Butyl amine-1-C'^ 

 n-Butyl halide-1-C" 

 dt-n-Butyl-l-C" phthalate 

 di-n-Butyl sebacate-1-C" 



