Ethanol analysis

Fig. 5. Ethanol analysis by GC compared to proposed free enzymes FIA system.

The free enzyme-FIA system applied to ethanol analysis presented good results, with high reproducibility and reliability in the range of 0.05-1.0 g of ethanol/L with a relative SD of 3.5%. The methodology developed to immobilize AOD on functionalized glass beads presented high retention efficiency of the protein, about 95.14 2.85%. The new, proposed,... 

At time intervals of 0,3,6,24,48,72,96, and 16 8h, a 2-mL aliquot was removed aseptically from each flask. The samples were centrifuged, and the supernatants were filtered for sugar analysis on HPLC and ethanol analysis by gas chromatography (GC). At the last time point, a sample from each SSF flask was streaked on a YPD (yeast extract, peptone, dextrose)... 

EN93 Detwiler, R., Casper, S., Daniel, D., Kanaley, J., Mostek, S., Rose, G., Silva, D., Volger, G. and Warren, K. (1992). Development of the Kodak Ektachem clinical chemistry slides for ethanol analysis. Clin. Chem. 38, 1049-1050, Abstr. 491. 

Serum (or plasma) is the most common specimen for ethanol analysis by ADH methods the method also performs well with urine or saUva. In some methods, whole blood may be used directly, but in others, a precipitation step may be required before analysis to avoid interference from hemoglobin. These methods generally compare closely with gas chromatographic methods. ... 

For isolated cases, the first indication of the presence of a volatile substance may be the presence of an unknown peak when a sample is analyzed for ethanol and other volatile alcohols (see the previous section). In these instances, method development focuses on the compound encountered and frequently involves modification of the ethanol analysis procedure. Numerous procedures for single VOCs or classes of VOCs have been developed and summarized in review articles. HS-GC remains the most frequently used... 

The experiment involves periodic sampling of the solution in the reaction flask. With a syringe, a sample is extracted for ethanol analysis in a calibrated gas chromatograph (Bendix 2600 with 6 foot Porapak S column). At the same time, the solution is titrated with Karl Fisher reagent to give semiquantitative water analysis. The data collected are plotted in Figure 2. 

Kugelberg, F.C. Jones A.W. (2007) Interpreting Results of ethanol analysis in postmortem specimens A review of literature. Foresic Science International. 165,10-29. 

Microbial contamination The impact that microbial contamination makes can depend on the nature of the sample and the analysis. Biological samples can be affected profoundly by microbial contamination ethanol analysis in urine can be affected by elevated levels by microbial contamination. Fluoride is used to inhibit growth and alcohol production. Water samples are similarly affected by the growth of microorganisms for various analytes. 

Berg C. World fuel ethanol analysis and outlook. 2004. http //www.distiU.com/World-Fuel-Ethanol-A 0-2004.html. 

For ethanol analysis by transmission NIR spectroscopy, good results were obtained, with SEC = 0.16%, simple correlation coefficient (r) = 0.998, and standard error of prediction (SEP) = 0.16% with first-derivative values of the optical data obtained at the wavelength of 1672 nm. The ethanol content of low-alcohol beers defined as < 1 v/v% could also be measured by NIR to the same accuracy, but this might not be sufficient for alcohol-free beers defined as <0.05%, although, for ethanol analysis by transflectance NIR, good results were also obtained with SEC = 0.08%, R = 0.999, and SEP =0.16% with first-derivative values of the optical data obtained at the wavelengths of 1672 and 1212 nm. Ethanol can be measured accurately and precisely in beer by both transmission and transflectance NIR methods. 

Reconstitute residue into 100 ul ethanol. Analysis by GC—NPD, GC-MS, and LC-QTOFMS. 

From C. Berg, World Fuel Ethanol - Analysis and Outlook. 2004, www.distill.com. Reproduced with permission from C. Berg, F.O. Licht. 

Tsang SC, Bulpitt C. Rare earth oxide sensors for ethanol analysis. Sens. Actuators, B Chemical. 1998 52 226-235. DOI 10.1016/S0925-4005(98)00233-0. 

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