Method Mumber E-294 SORBIC ACID RECONSTITUTED LEAF (Automated Colorimetric Method) INTRODUCTIION ANDSUMMARY Sorbic acid is determined colorimetrically the AutoAnalyzer_ is extracted with ground sample of reconstituted an aqueous acetic tobacco the AutoAnalyzer II extract is submitted acid solution. The filtered wnere color development automatically. The absorbance measurement and are done dichromate-sulfuric acid dehyde sorbic acid is oxidized with potass ona which reacts with 2-thiobarbituric acid form product which red colored Interfering background absorbance is eliminated by at 530 on-Tine absorbs nm. dialysis_ Nitrates alkaloids tota] reducing phosphorus and sugars urea , portion 0f the amonia may be determined extract (Method Mumbers same A-16, E-ID, E-49, E-57 and E-56, respectively) _ The average recovery Of sorbic acid added to RCB monitor was 98.98 The relative standard deviation at che two-sigma Teve] was #4% for experimenta| samples and #4% for RCB monitor' samp SAMPLEREQUIREMENTS II. Tota] 2 grams sampie recomended: Samp]e recomended per determination: 0.5 gram Replicate determinations Iy made: norma grams : Man-hours per determination: 0.4 hour : Man-hours for replicates: 0.5 hour/2 determinations Tota] elapsed time: 0.5 hour/2 determinations 8 12/81
Method Mumber E-294 SORBIC ACID RECONSTITUTED LEAF (Automated Colorimetric Method) INTRODUCTIION ANDSUMMARY Sorbic acid is determined colorimetrically the AutoAnalyzer_ ground sample of reconstituted tobacco is extracted with an aqueous acetic the AutoAnalyzer II wnere acid solution. The filtered extract is submitted color development and absorbance measurement are done automatically. The dichromate-sulfuric acid ona dehyde sorbic acid is oxidized with potass which reacts with 2-thiobarbituric acid form red colored product which absorbs at 530 nm. Interfering background absorbance is eliminated by on-Tine dialysis_ Nitrates alkaloids tota] reducing sugars urea , phosphorus and portion 0f the same extract (Method Mumbers amonia may be determined A-16, E-ID, E-49, E-57 and E-56, respectively) _ The average recovery Of sorbic acid added to RCB monitor was 98.98 The relative standard deviation at che two-sigma Teve] was #4% for experimenta| samples and #4% for RCB monitor' samp II. SAMPLEREQUIREMENTS Tota] sampie recomended: 2 grams Samp]e recomended per determination: 0.5 gram Replicate determinations norma Iy made: grams : : 8 Man-hours per determination: 0.4 hour Man-hours for replicates: 0.5 hour/2 determinations Tota] elapsed time: 0.5 hour/2 determinations 12/81