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PubMed2003

The effect of distillation and line cleaning on the quality of water emitted from dental units.

PURPOSE: To monitor water emitted from dental units connected to centralized water distillation units fitted with reservoirs for dispensing chemicals designed to control biofilms. METHODS: Three private practice dental offices participated in the study. None of the office operatories had independent water reservoir (bottle) systems or any other type of water treatment equipment. Initially, 5.0 mL water specimens were obtained from the handpiece and three-way syringe service lines as well as from the sink faucets in three operatories in each office. Specimens were collected at the end of the workweek. Specimens were neutralized for residual chlorine, diluted and spiral plated onto R2A agar. Aerobic incubation was allowed for 7 days at 21 degrees C. Numbers of colonies were then determined and expressed as CFU/mL. If water specimens containing more than 200 CFU/mL were detected, the offices were equipped with water distillers with attached cleaning solution dispensers. The units allowed distilled water to move under normal pressure to all connected dental units. When cleaning, the distillers were inactivated, which allowed cleaning fluid to move under pressure from the dispensers through all unit waterlines. The waterline-cleaning scheme followed the manufacturer recommendations. The presence of no more than 200 CFU/mL in emitted water was then established and a regimen of weekly cleanings applied for 3 weeks. Water specimens were always collected on the last workday of the week. Then, cleaning was suspended and weekly monitoring performed. Cleaning was restored immediately after detection of more than 200 CFU/mL. RESULTS: Levels of microbial contamination prior to the initiation of cleaning indicated marked variability (720-332,000 CFU/mL) and that water containing less than 200 CFU/mL was not being emitted from any operatory water source. However, sought-after water was consistently obtained over a period of 3 weeks from all unit sources after line-cleaning processes were completed. Water containing less than 200 CFU/mL was obtained from all unit sources in the three offices after skipping of one weekly cleaning. In one office, cleaning was suspended for 3 weeks without affecting water quality. Resumption of weekly cleanings produced desirable water from all sources in the three offices within 2 weeks. Results indicate that dental units attached to centralized combined water distillation-cleaning solution distribution systems can produce water with less than 200 CFU/mL and that the missing of one weekly cleaning did not negatively affect water quality.

Biofilms↗

PubMed2006

[A large amount of distilled water ineffective for prevention of bladder cancer cell implantation at the time of transurethral resection].

A previous study indicated that distilled water could prevent bladder tumor cell implantation in an in vitro assay. We investigated whether a large amount of distilled water irrigation prevented recurrence of superficial bladder cancer in the clinical setting and then we estimated whether cancer cell implantation at the time of transurethral resection is a major mechanism of recurrence. Between May 2000 and January 2002, 22 patients with primary, superficial bladder carcinoma who underwent transurethral resection of bladder tumors (TURBT) were enrolled in this study. The patients underwent bladder washout with 1,000 ml distilled water immediately after TURBT, and then intravesical irrigation with 3,000 ml water for three hours. Control patients were randomly chosen from those who previously underwent TURBT in our hospital and had similar prognostic factors. The 1- and 2-year recurrence-free rates in the patients undergoing distilled water irrigation were both 45% and those in the control patients were 65% and 45%, respectively. There were no significant differences between the two groups. This result indicates that distilled water was ineffective in preventing recurrence of superficial bladder tumor.

Adult↗

PubMed2006

Natural compounds obtained through centrifugal molecular distillation.

Soybean oil deodorized distillate (SODD) is a byproduct from refining edible soybean oil; however, the deodorization process removes unsaponifiable materials, such as sterols and tocopherols. Tocopherols are highly added value materials. Molecular distillation has large potential to be used in order to concentrate tocopherols, because it uses very low levels of temperatures because of the high vacuum and short operating time for separation and, also, it does not use solvents. However, nowadays, the conventional way to recover tocopherols is carrying out chemical reactions prior to molecular distillation, making the process not so suitable to deal with natural products. The purpose of this work is to use only molecular distillation in order to recover tocopherols from SODD. Experiments were performed in the range of 140-220 degrees C. The feed flow rate varied from 5 to 15 g/min. The objective of this study was to remove the maximum amount of free fatty acids (FFA) and, so, to increase the tocopherol concentration without add any extra component to the system. The percentage of FFA in the distillate stream of the molecular still is larger at low feed flow rates and low evaporator temperatures, avoiding thermal decomposition effects.

Centrifugation↗

PubMed1986

Long-lasting protective effect of slow-release theophylline on asthma induced by ultrasonically nebulized distilled water.

We investigated the intensity and duration of the effect of a single dose of slow-release theophylline on bronchial hyperresponsiveness to ultrasonically nebulized distilled water in asthma. In six subjects with a history of mild asthma, we measured airway responsiveness to ultrasonically nebulized distilled water and serum theophylline at 4, 8, and 12 hours after treatment with placebo or slow-release theophylline (10 +/- 1 mg/kg, orally). To assess bronchial responsiveness, dose-response curves were established by plotting the baseline value of FEV1 and the largest FEV1 after each doubling dose of nebulized distilled water against the dose of nebulized water. The degree of bronchoconstriction induced by ultrasonically nebulized distilled water was significantly inhibited at 4, 8, and 12 hours after treatment with theophylline, at serum levels of 14.8 +/- 4.6, 14.4 +/- 2.8, and 12.0 +/- 2.5 micrograms/mL theophylline (mean +/- SD). Tremor occurred in three patients and was associated with nausea, epigastric pain, and tachycardia in one of them. We conclude that a single dose of slow-release theophylline has a prolonged protective effect on bronchoconstriction induced by ultrasonically nebulized distilled water, but in some subjects is associated with side effects that limit its clinical usefulness.

Asthma↗

PubMed1984

Bronchial challenge with hypertonic KCl solution in the diagnosis of bronchial asthma. A comparison with the challenge performed by inhalation of distilled water.

97 symptom-free asthmatics, 56 patients with chronic bronchitis and 32 healthy persons were challenged by inhalation of ultrasonically nebulised hypertonic KCl solution. 24 patients out of the group of asthmatics were challenged also by the inhalation of distilled water to compare its bronchial effect and diagnostic value in bronchial asthma with those of hypertonic (10%) KCl solution. KCl solution caused positive bronchial reaction in each patient with asthma after less than 100 inhalations. The increase of airway resistance (Raw) showed a dose dependence in contrary to bronchitics and healthy persons who failed to show any positive bronchial reaction in any of the cases. Distilled water induced a much lower increase in Raw than 10% KCl solution in the same doses inhaled in each patient with asthma, i.e. more inhalations (longer time) were needed to reach a positive bronchial reaction. The bronchial sensitivity against KCl solution and distilled water did not show clear-out parallelism. The results suggest that the positivity of challenge test performed by the inhalation of hypertonic KCl solution - similarly to that of distilled water (published by others) - seems to be specific for asthma. Challenge test performed with 10% solution has advantages relative to that performed by distilled water, primarily because of the non negligible proportion of false negativity of the latter in the group of asthmatics.

Asthma↗

PubMed1980

Improvements to assisted distillation cleanup of pesticide residues in animal fats.

The assisted distillation technique, which was developed for the cleanup of pesticide residues from animal fats, has been improved. Nitric acid cleaning of distillation tubes resulted in a significant improvement in the recoveries of hexachlorobenzene (HCB) and lindane (from 76 to 92% and 84 to 89%, respectively). A larger U-tube condenser was developed that condensed 100% of all pesticides studied. With this new condenser, a study of distillation tube flow rates showed that pesticide recoveries at 600 mL nitrogen/min were generally better than those obtained at any other flow rate although recoveries were satisfactory at 400 and 800 mL/min. Recoveries of pesticides at distillation temperatures of 210-240 degrees C were obtained with tubes cleaned with nitric acid, and using the larger U-tube condenser. The distillation temperature of choice was again 230 degrees C because there was little variation from 220 to 240 degrees C.

Adipose Tissue↗

PubMed2006

The effect of increased yeast alcohol acetyltransferase and esterase activity on the flavour profiles of wine and distillates.

The fruity odours of wine are largely derived from the synthesis of esters and higher alcohols during yeast fermentation. The ATF1- and ATF2-encoded alcohol acetyltransferases of S. cerevisiae are responsible for the synthesis of ethyl acetate and isoamyl acetate esters, while the EHT1-encoded ethanol hexanoyl transferase is responsible for synthesizing ethyl caproate. However, esters such as these might be degraded by the IAH1-encoded esterase. The objectives of this study were: (a) to overexpress the genes encoding ester-synthesizing and ester-degrading enzymes in wine yeast; (b) to prepare Colombard table wines and base wines for distillation using these modified strains; and (c) to analyse and compare the ester concentrations and aroma profiles of these wines and distillates. The overexpression of ATF1 significantly increased the concentrations of ethyl acetate, isoamyl acetate, 2-phenylethyl acetate and ethyl caproate, while the overexpression of ATF2 affected the concentrations of ethyl acetate and isoamyl acetate to a lesser degree. The overexpression of IAH1 resulted in a significant decrease in ethyl acetate, isoamyl acetate, hexyl acetate and 2-phenylethyl acetate. The overexpression of EHT1 resulted in a marked increase in ethyl caproate, ethyl caprylate and ethyl caprate. The flavour profile of the wines and distillates prepared using the modified strains were also significantly altered as indicated by formal sensory analysis. This study offers prospects for the development of wine yeast starter strains with optimized ester-producing capability that could assist winemakers in their effort to consistently produce wine and distillates such as brandy to definable flavour specifications and styles.

Acetyltransferases↗

PubMed1997

Effects of distilled water and mixture of sorbitol-mannitol irrigation fluids on fluid-electrolyte balance in patients undergoing transurethral prostatectomy.

This study aimed to compare two various irrigation fluids used in transurethral prostatectomy (TURP) with respect to changes in fluid-electrolyte balance and to evaluate the blood loss during TURP. TURP was performed in 50 patients using distilled water and in 42 patients using a mixture of sorbitol and mannitol solution (2.7% sorbitol and 0.54% mannitol) as irrigation fluid. Fluid-electrolyte changes and blood loss were evaluated. None of the patients had transurethral resection syndrome. Decline in serum sodium level was more significant in patients who were operated on with the sorbitol plus mannitol irrigation fluid in contrast to its clinical insignificance (p < 0.05). Decrease in serum sodium concentration in patients with more than 15 g of tissue resected was greater than in patients with less than 15 g of tissue resected (p < 0.05). Blood loss was greater in the distilled water group (p < 0.05). Blood loss was 145.5 +/- 3.4 ml in patients given a blood transfusion. In conclusion, a fluid containing mainly sorbitol must be the irrigation fluid preferred over distilled water because of its non-haemolytic nature, but although not important clinically, it can cause hyponatraemia more than distilled water. Furthermore, it is useful to determine blood loss during TURP before deciding to give a blood transfusion.

Aged↗

PubMed2005

Ultrasonically nebulized distilled water prevents exogenous histamine hyperreactivity in Toxocara canis-infected mice.

OBJECTIVE: This study examines the effect of ultrasonically nebulized distilled water inhalation on the systemic histamine hyperreactivity of Toxocara canis-infected mice. METHODS: Uninfected and T. canis-infected mice received an intravenous sublethal dose of histamine and lethality rates were documented. At 24 days post infection, infected mice received ultrasonically nebulized distilled water inhalation for 1 h. Twenty-four hours later histamine levels were determined in bronchoalveolar lavage fluid as well as histamine lethality and toluidine blue-stained mast cell number in the lung. RESULTS: T. canis-infected mice showed increased lethality after exposure to histamine in comparison to uninfected mice. Ultrasonically nebulized distilled water inhalation prevented histamine-induced lethality and reduced toluidine blue-stained mast cell numbers in the lung. CONCLUSIONS: The correlation between decreases in stained mast cells in the lung after ultrasonically nebulized distilled water inhalation and inhibition of histamine-induced lethality in these animals suggests participation of mast cells in the phenomenon and could be helpful in understanding the mechanisms of hyperreactivity during helminth parasite infections.

Anaphylaxis↗

PubMed1987

Vapor compression distiller and membrane technology for water revitalization.

Water revitalization for a space station can consist of membrane filtration processes and a distillation process. Water recycling equipment using membrane filtration processes was manufactured for ground testing. It was assembled using commercially available components. Two systems for the distillation are studied; one is an absorption type thermopervaporation cell and the other is a vapor compression distiller. Absorption type thermopervaporation able to easily produce condensed water under zero gravity was investigated experimentally and through simulated calculation. The vapor compression distiller was studied experimentally and it offers significant energy savings for evaporation of water.

Absorption↗

PubMed1988

Ultrastructural changes of synaptic glomeruli following intrathecal injection of distilled water to rats.

We attempted to identify synaptic glomeruli in the spinal substantia gelatinosa of rats by injecting distilled water into the subarachnoid space. The altered synaptic glomeruli were visualized when injecting 1.0 ml of distilled water, though the incidence of degenerative synaptic glomeruli was rare in the case of an injection of 0.5 ml or less. We assume that when the distilled water is injected, there is a sudden change in homeostatic balance in cerebrospinal fluid, following inhibition of nerve impulses in the dorsal root and the altered synaptic glomeruli. Ultrastructurally, the injection of distilled water led to a preferential degeneration of synaptic glomeruli derived from the C-fibers.

Animals↗

PubMed2005

Determination of volatile compounds in grape distillates by solid-phase extraction and gas chromatography.

Solid-phase extraction (SPE) procedure on octadecylsilica (C18) was developed for accumulation of volatile compounds from grape distillates. The procedure was optimised for final analysis by capillary gas chromatography. At mass concentrations in model solutions ranging from 0.1 to 50 mg/l solid-phase extraction recoveries of all analytes ranged from 69% for 2-phenylethanol to 102% for capric acid, with RSD values from 2 to 9%. SPE recoveries of internal standards to be added in the sample solution prior to extraction, higher alcohols 2-ethyl-1-hexanol and 1-undecanol, were 97 and 93%, respectively, with RSD values of 3%. Detection limits of analyzed compounds in model solutions ranged from 0.011 mg/l for isoamyl acetate to 0.037 mg/l for caproic acid. Method efficiency was tested in relation to acetic acid content, volume fraction of ethanol and possible matrix effects. A significant influence of matrix on SPE efficiency for geraniol, cis-2-hexen-1-ol and cis-3-hexen-1-ol was detected. For the same reason, 2-phenylethanol could not be determined by developed SPE method in samples of grape distillates. The developed solid-phase extraction method was successfully applied to determine the differences in volatile compound content in different grape distillates produced by the distillation of crushed, pressed and fermented grapes.

Adsorption↗

PubMed2005

An improved microwave Clevenger apparatus for distillation of essential oils from orange peel.

Microwave Clevenger or microwave accelerated distillation (MAD) is a combination of microwave heating and distillation, performed at atmospheric pressure without added any solvent or water. Isolation and concentration of volatile compounds are performed by a single stage. MAD extraction of orange essential oil was studied using fresh orange peel from Valencia late cultivar oranges as the raw material. MAD has been compared with a conventional technique, which used a Clevenger apparatus with hydro-distillation (HD). MAD and HD were compared in term of extraction time, yields, chemical composition and quality of the essential oil, efficiency and costs of the process. Extraction of essential oils from orange peels with MAD was better in terms of energy saving, extraction time (30 min versus 3 h), oxygenated fraction (11.7% versus 7.9%), product yield (0.42% versus 0.39%) and product quality. Orange peels treated by MAD and HD were observed by scanning electronic microscopy (SEM). Micrographs provide evidence of more rapid opening of essential oil glands treated by MAD, in contrast to conventional hydro-distillation.

Chemical Fractionation↗

PubMed2006

Gas chromatographic quantification of aliphatic aldehydes in freshly distilled Calvados and Cognac using 3-methylbenzothiazolin-2-one hydrazone as derivative agent.

A new precise and sensitive method was used for the quantification of aliphatic aldehydes from C5 to C11 in highly ethanolic beverages such as freshly distilled spirits. Carbonyl compounds were derivatized using 3-methylbenzothiazolin-2-one hydrazone (MBTH) and then separated and detected by gas chromatography-mass spectrometry (GC-MS). Selective mass spectrometric detection of molecular ions of derivatives was performed to obtain a good sensibility (0.2-1.2 microg l(-1)) and a good selectivity. For a concentration of 20 microg l(-1), relative standard deviations were lower than 10% except for heaviest compounds (decanal and undecanal) where RSD were between 11 and 13%. The concentrations of aliphatic aldehydes were determined in nine samples of freshly distilled Calvados and two samples of freshly distilled Cognac with highest concentrations reported for 3-methylbutanal (from 170 to 1220 microg l(-1) in Calvados and from 1540 to 5500 microg l(-1) in Cognac). 3-Methylbutanal and hexanal, due to their low detection thresholds, could be important olfactive markers of these two products. Less than 1h30 is required to quantify the nine studied aliphatic aldehydes in freshly distilled spirits.

Alcoholic Beverages↗

PubMed2003

Green chemical engineering aspects of reactive distillation.

Reactive or catalytic distillation technology combines chemical synthesis steps with separations by distillation. This combination can lead to intensified, high-efficiency process systems with significant green engineering attributes. New applications and understanding have prompted growth in the use of reactive distillation for a variety of chemical syntheses, especially esterifications and etherifications involving oxygenated hydrocarbons. We describe several applications and the potential and tradeoffs for reactive distillation technology in the context of green engineering principles.

Catalysis↗

PubMed2005

Reducing CO2 emissions and energy consumption of heat-integrated distillation systems.

Distillation systems are energy and power intensive processes and contribute significantly to the greenhouse gases emissions (e.g. carbon dioxide). Reducing CO2 emissions is an absolute necessity and expensive challenge to the chemical process industries in orderto meetthe environmental targets as agreed in the Kyoto Protocol. A simple model for the calculation of CO2 emissions from heat-integrated distillation systems is introduced, considering typical process industry utility devices such as boilers, furnaces, and turbines. Furnaces and turbines consume large quantities of fuels to provide electricity and process heats. As a result, they produce considerable amounts of CO2 gas to the atmosphere. Boilers are necessary to supply steam for heating purposes; besides, they are also significant emissions contributors. The model is used in an optimization-based approach to optimize the process conditions of an existing crude oil atmospheric tower in order to reduce its CO2 emissions and energy demands. It is also applied to generate design options to reduce the emissions from a novel internally heat-integrated distillation column (HIDiC). A gas turbine can be integrated with these distillation systems for larger emissions reduction and further energy savings. Results show that existing crude oil installations can save up to 21% in energy and 22% in emissions, when the process conditions are optimized. Additionally, by integrating a gas turbine, the total emissions can be reduced further by 48%. Internal heat-integrated columns can be a good alternative to conventional heat pump and other energy intensive close boiling mixtures separations. Energy savings can reach up to 100% with respect to reboiler heat requirements. Emissions of these configurations are cut down by up to 83%, compared to conventional units, and by 36%, with respect to heat pump alternatives. Importantly, cost savings and more profit are gained in parallel to emissions minimization.

Air Pollution↗

PubMed2002

Rapid analysis of methanol in grape-derived distillation products using near-infrared transmission spectroscopy.

Samples of distillates derived from the production of wine-fortifying spirit were analyzed for methanol by gas chromatography (GC) and near-infrared spectroscopy (NIRS). NIRS calibration models were developed which could accurately predict methanol concentrations in samples of fortifying spirit that had been produced over a period of three years from four different commercial distillation facilities. The best accuracy of the predictive models, as measured by the standard error of prediction value, was 0.06 g/L methanol. Other distillation fractions, produced during preparation of commercial fortifying spirit, were also examined. The most useful NIRS calibration models used partial least squares regression on continuous spectra from a scanning instrument, but it was demonstrated that calibrations could also be developed with a smaller number of fixed wavelengths, using multiple linear regression models. NIRS offers the advantages of rapid analysis, with simple routine operation, and may offer the potential for in-line process control in the operation of a commercial distillation facility.

Calibration↗

PubMed2002

Selection of yeast starter culture strains for the production of marula fruit wines and distillates.

Juice of the Sclerocarya birrea subsp. caffra (marula) fruit was fermented by indigenous microflora and different commercial Saccharomyces cerevisiae yeast strains at different temperatures, namely, 15 and 30 degrees C. Volatile acids, esters, and higher alcohols were quantified in the wine and distillates, and the results were interpreted using a multivariate analysis of variance and an average linkage cluster analysis. Significant differences between 15 and 30 degrees C and also among yeasts with respect to volatile compounds were observed. Yeast strains VIN7 and FC consistently produced wines and final distillates significantly different from the other strains. A panel of tasters and marula and brandy producers was asked to select wines and distillates that had an acceptable and typical marula "nose". They were also asked to detect the differences among wines and distillates fermented with the same yeast strain at different temperatures.

Acetaldehyde↗