Rapid Distillation Research Articles

Recovery of FLiBe from ThF4-FLiBe salt using precipitation-distillation coupled method.

The low-pressure distillation of FLiBe salt containing ThF4 was carried out at 1223 K and <10 Pa using thermogravimetric equipment. The weight loss curve indicated a rapid distillation stage at the beginning of distillation, followed by a slow stage. The composition and structure analyses showed that the rapid distillation process originated from the evaporation of LiF and BeF2, while the slow distillation process was mainly attributed to the evaporation of ThF4 and LiF complexes. Precipitation-distillation coupled method was employed for the recovery of FLiBe carrier salt. XRD analysis indicated that ThO2 was formed and remained in the residue with the addition of BeO. Our results showed that the combination of precipitation and distillation treatment was an effective way to recover carrier salt.

The evaporation behaviour of ThF4 mixed of FLiNaK melt during low-pressure distillation

Low-pressure distillation of FLiNaK melt containing 50 wt % ThF4 was carried out at 910 °C and <10 Pa using thermogravimetric equipment. The weight loss curve indicated clearly two stages: a rapid distillation stage in the initial period following a very long slow stage. The analysis results showed the rapid distillation originated from the evaporation of FLiNaK, while the slow process was attributed to the evaporation of ThF4 and FLiNaK complexes. Because of the co-evaporation of ThF4 and FLiNaK, it seems not feasible to separate ThF4 from mixture salt. Hence, FLiNaK and ThF4 may be recovered simultaneously by distillation.

Alcohol Determination of Malt-Based Beverages by Rapid Distillation

ABSTRACTThe objective of the study was to assess a rapid distillation unit as an alternative to standard distillation (Beer-4A). A rapid distillation unit (Vapodest 200 by Gerhardt Analytical Systems) was selected as an alternative for its ability to rapidly distill using the power of steam. The NIR/density method (Beer-4G) is quite suitable for measuring the alcohol content of beer; however, flavored malt beverages present a challenge. Deviations between results by the NIR/density method versus results by distillation can occur due to flavor additions and/or high alcohol content. A more accurate way to measure alcohol in this type of product is to first perform a standard distillation (Beer-4A). Unfortunately, this method is time consuming and labor intensive. A precision study was performed to determine repeatability and reproducibility. Three analysts distilled five malt-based products including both beer and flavored malt beverages with alcohol levels ranging from 4.2 to 14.4% (v/v). Repeatability and reproducibility coefficients of variation for the determination of alcohol for this range were 0.05–0.23% and 0.11–0.19%, respectively. In addition, results from Beer-4A and rapid distillation were assessed using a paired t test for alcohol levels ranging from 3.6 to 14.4% (v/v). The P value of 0.30 indicated that there was not a statistically significant difference between the means of the data sets at a 95% confidence level.

Electron beam-assisted cracking of synthetic paraffins

The electron beam-initiated cracking of a mixture of C17–C120 paraffins at 350–370°C has been studied. The cracking regime implied simultaneous feedstock irradiation and rapid distillation of fragmentation products from the irradiation zone. The distillate was a mixture of 61.5 wt % alkanes and 38.5 wt % alkenes. The product molecule contained on average 13 carbon atoms. The gasoline fraction in the condensate was 32.3 wt %. It was demonstrated that the product composition can be changed depending on the geometric parameters of reaction equipment and temperature distribution at the reactor outlet.

RAPID DISTILLATION COUPLED WITH ION CHROMATOGRAPHY FOR THE DETERMINATION OF SIX ALKYLAMINES IN COSMETICS

A rapid distillation method coupled with ion chromatography was developed for simultaneous determination of methylamine, ethylamine, dimethylamine, trimethylamine, propylamine, and butylamine in cosmetics. The distillation system was designed professionally to achieve rapid distillation in less than 3 min and eliminate the interferences of alkali metals, alkaline earth, and organic compounds effectively. Samples were distilled using vapor stream under alkaline conditions and the distilled products were absorbed in acetic acid solution prior to detection. The linear ranges of alkylamines were within 0.1–18 mg/L and the detection limits ranged from 0.045 mg/L to 0.075 mg/L. The method was successfully utilized to determine the amount of alkylamines in commercial cosmetics without need for tedious pretreatments. Average recoveries ranged from 84.4% to 108.5% with relative standard deviations (RSD) in the range of 0.7–7.6%. Validation results indicated that the method was simple, accurate, precise, selective, and suitable for the determination of alkylamines in cosmetics.

A rapid distillation method coupled with ion chromatography for the determination of total sulphur dioxide in foods

A rapid distillation method coupled with ion chromatography for the determination of total sulphur dioxide in foods was developed. The distillation was performed using vapour and carbon dioxide stream released from the reaction between sodium carbonate and sulphuric acid. The distilled product was captured in sodium hydroxide solution and sulphur dioxide was measured as sulphite by ion chromatography. The linearity ranged from 0.051 to 32.1 mg L −1 SO 2 and limit of detection was 0.013 mg L −1. This method was successfully applied to the determination of total sulphur dioxide in preserved foods, dried vegetables, vermicelli and wines. The recovery ranged from 76.7% to 104.8% with the relative standard deviation of 0.7–8.2%. The distillation procedure was rapidly achieved within 3 min without blowing nitrogen or air. The method presented advantages of time-saving and simplification working process compared to the conventional method and is already used as China National Standard Method.

Rapid and Inexpensive Steam Distillation Method for Routine Analysis of Inorganic Nitrogen in Alkaline Calcareous Soils

Determination of inorganic nitrogen (N) in soil is important in making N fertilizer recommendations for crops. To find a rapid, reliable, and economical method for the estimation of inorganic N in alkaline calcareous soils of Pakistan, three steam distillation methods were compared using soils varying in ammonium (NH4) and nitrate (NO3) N contents and other physicochemical properties. In the standard method, the soil sample is shaken with 2 N potassium chloride (KCl) for 1 h, and the extract is then analyzed by steam distillation. In the other two methods, the soil sample is distilled directly with either 2 N KCl or distilled/deionized water. Based on the results of the present work, a method that involves steam distillation with only distilled/deionized water and that requires half the quantity of magnesium oxide (MgO) of the standard method has been proposed, as all the three methods yielded identical results for NH4- and NO3-N contents. Being economical, the proposed method for inorganic N estimation by direct distillation of soil with distilled/deionized water deserves consideration for adoption by soil-testing laboratories.

Microwave mediated distillation with solid-phase microextraction: determination of off-flavors, geosmin and methylisoborneol, in catfish tissue

Presented is a rapid distillation device for use with solid-phase microextraction (SPME). We apply this device specifically for determining two semivolatile off-flavor compounds, methylisoborneol and geosmin, in channel catfish. The presence of these two compounds in channel catfish filets results in unwelcome tastes. In the presented procedure, a catfish tissue sample is placed within a sample container located inside the microwave device. Microwave radiation is applied and distillates formed migrate through a condenser via a purge gas and are collected in a sample vial. A SPME fiber is placed within the stirred collected distillate and methylisoborneol and geosmin are extracted. Qualitative and quantitative results of these extractions are obtained using a gas chromatograph-ion trap mass spectrometer. This solventless technique results in detection limits far below the human threshold for these off-flavor compounds in channel catfish.

A Comparison of Three Methods for Determining Total Sulfur Dioxide in White Wine

Three methods were tested for their suitability as alternatives to the standard Monier-Williams (M-W) distillation for the determination of sulfur dioxide in white wines. The alternatives tested were: <i>(1)</i> high performance liquid chromatography (HPLC); <i>(2)</i> aeration-oxidation; and <i>(3)</i> rapid distillation followed by redox titration. Standard sulfite solutions and wine samples were analyzed by all four techniques. Results from HPLC and M-W methods were in close agreement. When analyzing by aeration-oxidation, a correction factor had to be introduced to obtain comparable results with the M-W distillation. The rapid distillation was not a suitable replacement for the M-W procedure.

A Comparison of Selected Methods for Determining Sulfite in Prawns

As the standard technique for sulfite analysis, the Monier-Williams distillation, is time consuming and relatively insensitive, many alternative methods have been developed. Three of these methods were tested for their suitability for the routine determination of residual sulfite in prawns: i) a rapid steam distillation; ii) high performance liquid chromatography (HPLC), and iii) an enzyme-based procedure. Testing of the three selected methods involved analyses of standard sulfite solutions, prawns of known sulfite levels and prawns of unknown sulfite levels and comparison of results with those determined by the Monier-Williams procedure. Statistical analysis showed that the sulfite levels determined on standard solutions by rapid distillation were in close agreement with those obtained by the Monier-Williams distillation. However, a correction factor had to be introduced when analyzing prawns by the rapid distillation method to obtain comparable results with those produced by the Monier-Williams distillation. The same statistical analysis performed on levels determined by HPLC and the Monier-Williams distillation gave close agreement for both standard solutions and prawns. The enzyme test, after promising results for the standard solutions, proved to be unsatisfactory for analysis of sulfite in prawns.

A modified distillation method for the detection of fat oxidation in foods

SummaryA rapid distillation procedure for the estimation of fat oxidation in food using the 2‐thiobarbituric acid test has been developed. The apparatus generates steam rapidly and allows high sample throughput while minimizing cleaning of glassware. Using the standard compound, tetramethoxypropane (TMP), and a number of food samples spiked with standard, the recovery of malondialdehyde was determined and suitable operating conditions selected. Levels of TMP equivalent to TBA numbers between 1 and 10 were used. Recovery of standard increased from 25.3% at 20 ml to 81.6% at 120 ml, and recoveries at different TBA numbers were similar. After consideration of various factors, 50 ml was chosen as the distillate volume and was collected in about 4 min. With food samples, the recovery varied depending on the composition of the food and, in order to determine TBA number, it was necessary to calculate recoveries from each type of sample. In the reaction of distillate with thiobarbituric acid, colour development was found to be extremely temperature sensitive, and careful temperature control of the heating bath was required.

Analysis of Sulfites in Shrimp Using Rapid Distillation Followed by Redox Titration

The use of rapid steam distillation followed by redox iodine titration provides a rapid and accurate determination of total sufite residual in shrimp. Values obtained for sulfite-treated shrimp using the rapid distillation method gave comparable results to those of the officially recognized Monier-Williams method. Values for the rapid distillation method ranged from 6 to 212 ppm while those of the Monier-Williams procedure ranged from 6 to 241 ppm for untreated and treated shrimps, respectively. Statistical analysis using two-sample Student's t-test indicated that there were no significant differences (p>0.05) for residual levels below 100 ppm but the values obtained by the rapid distillation method and the Monier-Williams procedure were significantly different (p<0.05) at concentrations near and above 100 ppm.

Analysis for Total Sulfite in Foods By Using Rapid Distillation Followed By Redox Titration

A rapid and accurate analysis for total sulfite as sulfur dioxide has been developed for foods and food products. The method, which combines a selective distillation cleanup procedure with the selective redox titration of sulfite ion by iodine, has been applied to a variety of foods and food products over a period of time with no significant interference encountered in any matrixes other than garlic and leeks. For the foods analyzed, the method typically shows a detection limit of 10 ppm, a relative standard deviation of 7.5% (compared with 10.4% for similar matrixes by the Monier-Williams method), and recoveries of 97.9 +/- 6.4%. Comparison of results for this method with those obtained using the Monier-Williams method showed a mean value for the distillation/titration method of 241 ppm compared with 242 ppm for the Monier-Williams method. A correlation of 0.991 and odds of a difference between methods of 10.7% (Student's paired t-test (1-alpha) X 100) were obtained for those matrixes where no interferences were encountered with either method.

Determination of volatile fatty acids by gas chromatography after a rapid steam distillation of wastes

Abstract Volatile fatty acids represent an essential consituent of anaerobic digestor liquors. An analytical procedure is presented to prevent drawbacks associated with direct aqueous injection of wastes on to a gas chromatograph. Precision and accuracy of the method are evaluated and compared with currently accepted procedures.

Separation and concentration of fluoride by distillation with hexamethyldisiloxane

A simple and rapid distillation method for the separation of fluoride is reported. The sample solution is treated with hexamethyldisiloxane and sulfuric acid, and the volatile trimethylfluorosilane thus formed is expelled with a nitrogen carrier gas without external heating and collected in an alkaline absorbing solution. Fluoride can be recovered quantitatively within 30 min without the serious dilution that accompanies steam distillation. Moreover, fluorine in the very dilute (ppb) solutions can be concentrated by this method. The interference of aluminum can be eliminated by the addition of phosphoric acid.

COLORIMETRIC FURFURAL MEASUREMENT AS AN INDEX OF DETERIORATION IN STORED CITRUS JUICES

Furfural arising in citrus juice as a result of deterioration during storage may be recovered and concentrated by rapid distillation and then calorimetrically determined by reaction with 10% aniline in acetic acid‐ethanol. As little as 25 μg per liter of furfural can be measured. The development of noticeable furfural parallels the development of off‐flavor and provides a useful numerical index for the extent of degradation. Results of a brief storage study on orange juice are reported.

Rapid Method for the Determination of Proof of Alcoholic Products Containing Dissolved Solids

Abstract A rapid and accurate method is described for determining proof of alcoholic products containing dissolved solids. Samples are distilled in a Jaulmes distillation unit and alcohol concentration is determined by a proof hydrometer. Shortened analysis time is due to the rapid distillation rate afforded by the Jaulmes unit. Recovery data and comparisons with results by a modified AOAC method are presented for 18 commercial alcoholic beverages. Results obtained, using the 2 methods, were in good agreement; a maximum difference in results of 0.4° proof was found for 2 of the 18 samples tested.

Rapid distillation separation of microgram quantities of fluoride

Rapid distillation separation of microgram quantities of fluoride

The rearrangement of allylic phosphines

Reduction of the allylic phosphine oxides, Ph2P(O)CR1R2·CH:CH2, with phenylsilane followed by rapid distillation gives the crude allylic phosphines, Ph2P·CR1R2·CH:CH2, which rearrange at 210° to the more stable phosphines Ph2P·CH2CH:CR1R2. This rearrangement is catalysed by traces of silanes or silanols; the pure allylic phosphines do not rearrange under these conditions. Diphenyl-1(1-phenylallyl)phosphine gave with methyl iodide the prototropically rearranged methyldiphenyl-(1-phenylprop-1-enyl)phosphonium iodide.

Petrology of Venus: Further Deductions

The spectrum of XeO/sub 4/ is reported. The typical isotope pattern of Xe is repeated every 16 mass units up to XeO/sub 4/. The exact mass of the tetroxide was verified further by reference to the spectrum of Hg. The fragmentation pattern varied very little with the energy of the ionizing beam of electrons. The volatility of XeO/sub 4/ was demonstrated by its very rapid distillation when a liquid nitrogen bath was replaced by one of dry ice. (P.C.H.)