The Analysis Committee has collaboratively tested local routine headspace gas chromatographic methods for the determination of the lower boiling point volatile compounds in beer. The repeatability values (r95) were dependent upon mean concentration (m) for acetaldehyde and alcohols but not for esters, ...
ML-1. By the same method, the sorbic acid and the ethanol solution of the unknown substance are prepared with a concentration of 2 * 10-3 mg mL-1. For the determination of 1cm 2 and record the cuvette with ethanol as reference ethanol as the reference, in the wavelength range of 210...
An improved method is proposed for the determination of boron in waters. The esterification reaction between boric acid and methanol in a concentrated sulphuric acid medium and the vaporisation of the methyl borate formed (boiling-point,... JR Castillo,JM Mir,C Martinez,... - 《Analyst》 被引...
Because of the boiling point of ionic-liquid at 75 °C, the highest temperature of ultrasonic temperature and heating temperature were below the boiling point. Concentration of C. sappan powder (70 mesh sieve) in [BMIM]Br methanol solution was 0.5 mol/L for five samples with ultrasonic extract...
After decompression, the boiling point of water is reduced, and the water can be evaporated at lower temperature. (2) this Law applies to colloidal sample, high temperature decomposed sample and more water sample, such as starch, bean product, canned food, syrup, honey, vegetable, fruit, ...
3.1. Evaluation of the type of dispersive and extraction solvents Initially, the selection of the type of dispersive and extraction solvents was performed combining acetone, acetonitrile, methanol or ethanol (dispersive solvents) with chloroform, carbon tetrachloride, 1,2-dichloroethane, monochlorobenzene ...
volatility volatile impurities removed during evaporation processes boiling point >20 C below that of the reaction/process solvent boiling point within ±20 °C of that of the reaction/process solvent boiling point >20 C above that of the reaction/process solvent ionizability impurities with different...
The gel was destained in the destain solution (40% ethanol, 10% acetic acid and 50% ddH2O) and shaken at room temperature for about 3 h, while the gel solution was changed five times during this period. Chromatography. Ion exchange, hydrophobic and size-exclusion chromato- graphy were ...
This effect can be explained by keeping in mind that the ethanol boiling point was approached. As the influence of temperature variations around 20 °C was negligible for the three analytes, and the sensitivity for ethanol determination was not critical, the heating step was not implemented, ...
ethanol, isopropanol, tetrahydrofuryl-2-carbionol, etc. or mixtures thereof. After cleaning or stripping the inadequately applied flux, the substrate is ready for re-application of the flux, step102. Suitable fluxes include rosin based fluxes, available from Alphametals of New Jersey, and no-clea...