Fructose standard solution

Glucose-fructose standard solution (GFS). Each individual team will need 100 mL of this solution. Weigh out exactly 0.090 g of glucose and 0.090 g of fmctose, dissolve both solids in distilled water contained in a 100-mL volumetric flask, and make up to the mark. Note that fmctose is somewhat hygroscopic it may be necessary to handle it in a dry-box if the humidity is unusually high. 

Sterile preparation of yeast invertase (50 mL per team) pH 4.8 to 5 acetate buffer 1 M sodium hydroxide 3,5-dinitrosalicylate reagent solution 1 MHCl glucose-fructose standard solution sucrose. 

Fig. 6 RI chromatogram of standard solution. 1 = sucrose 2 = citric acid 3 = glucose 4 = fructose 5 = lactic acid 6 = acetic acid 7 = ethanol. (From Ref. 36.)...

Standardization Prepare a Standard Solution containing a total of about 10% solids, using sugars of known purity (e.g., USP Fructose Reference Standard USP Dextrose Reference Standard, or NIST Standard Reference Material maltose, Aid-rich Chemical Company or equivalent) that approximates, on the dry basis, the composition of the sample to be analyzed. Dissolve each standard sugar, accurately weighed, in 20 mL of purified water contained in a 50-mL beaker. Heat on a steam bath until all sugars are dissolved, then cool, and transfer to a 100-mL volumetric flask. Dilute to volume with water and mix. Freeze the solution if it is to be reused. 

Assay Determine as directed under Lactose, Appendix X. Transfer about 2 g of sample, accurately weighed, to a 100-mL volumetric flask. Add 10 mL of fructose internal standard solution, dilute to volume with water, and mix. Perform the analysis within 24 h. 

Internal Standard Solution Prepare an aqueous solution of USP Fructose Reference Standard having a concentration of 100 mg/mL. 

Fructose Internal Standard Solution Prepare a solution of fructose to be used as an internal standard by transferring 50 g of commercial grade (3-D(-)fructose powder to a 500-mL volumetric flask, and dissolve in and dilute to volume with water. 

Repeatability Allow the chromatographic system to equilibrate at a flow rate of 2 mL/min, then inject 25-p.L aliquots of the Standard Solution. The chromatogram should show baseline resolution and a retention time for water of 1 to 2 min fructose, 2 to 3 min and lactose, 5 to 6 min. The coefficient of variation for the relative peak heights (lactose peak height/ fructose peak height) for ten injections should be <0.6% when column equilibration is complete. 

The reaction is also sensitive because can detect a low quantities like Ipg of fructose. The reaction also is specific because aldohexoses, aldopentoses, and ketopentoses do not interfere, however these compounds do not react even if its concentrations are higher, as Smg.mL-i. The sensitivity of the method is from 1 to 50pg of fructose. A standard solution of fructose is used to build the calibration curve and to get the equation of the linear regression to quantity samples. 

FTIR Citric and malic acid, glucose, fructose, sucrose Orange, grape, and apple juice, lemon drink, other soft drinks Sequential injection, convective interaction media (CIM) disk separation, multivariate calibration for spectral data resolution, inline calibration standard preparation from a single standard solution 0.2-9.0 g/L Lethanh and Lendl (2000)... 

The weights of other monosaccharides and reducing disaccharides which will reduce i ml. of this standard Fehling s solution are galactose, 0 00511 g- fructose. 0 00514 g.. mannose, 0 00431 g. lactose, 0 00678 g. maltose, 0 00807 g. 

Figure 9. Growth spread standard deviation vs mean growth rate from Shlau and Berglund (10) for fructose grown from aqueous solution.

For a determination of a, plot the absorbance measured for runs A2 and B1 to B5 versus the value of (n + /%)/2, where n[ and n are the numbers of moles of glucose and fructose added to the assay tube in the standardization runs. Since the GFS solution is made... 

Thio-D-fructofuranose (88) was prepared from 5-(9-tosyl-l,3-(9-isopropylidcnc-o -L-sorbopyranose (87) by the standard sequence of reactions shown in Scheme 26. The H and C NMR spectra of 88 in aqueous solution show only tlie signals of the furanose a and p anomers in the ratio of 11 89, whereas tlie NMR spectra of D-fructose in D2O show the presence of the -pyranose, -furanose, a-furanose, and a-pyranose in the ratio of 6 3 1 trace, respectively. Partial hydrolysis or methanolysis of 90, prepared from 1,6-di-O-tosyl-D-fructofuranose (89), gave 3,6-anhydro-l-deoxy-6-thio-D-oraZ)W7o (or D-yv/o)-hexulose (91). Nucleophilic attack of the ring sulfur atom on C-3... 

The use of phenyl p-o-glucopyranoside as internal standard and authentic samples of DFAs obtained by synthesis allowed determination of the corresponding response factors for quantitative analysis. The relative abundance of DFA diaster-eomers in a D-fructose caramel obtained by heating a concentrated solution of sucrose in the presence of 10% citric acid was found to correspond to a kinetic distribution, the ot-D-fructofuranose p-o-fructofuranose l,2 2,l -dianhydride 10 being the major component in the mixture (Fig. 4). 

The sensitivity of the method is from 100 to 500 ig.mL-i of reducing sugar. A standard glucose or fructose solution is used to build the calibration curve and get the straight line equation to quantify samples. 

For example, the standard reaction Gibbs energy for reaction A is the difference between the molar Gibbs energies of fructose-6-phosphate and glucose-6-phosphate in solution at 1 mol dm and 1 bar. 

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