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1.
A sensitive, simple and rapid method for ultra-trace determination of iron and manganese based on ultrasound assisted pseudodigestion in citric acid fermentation medium samples (beet and cane molasses and raw sugar based mediums) is described. Parameters influencing pseudo-digestion, such as sonication time, sample mass and solvent system were fully optimized. Final solutions obtained upon sonication were analyzed by electrothermal atomic absorption spectrometry (ETAAS). The best conditions for metal pseudo-digestion were as follows: a 25, 30 and 20 min sonication time for beet molasses, cane molasses and raw sugar based medium samples, respectively, 0.7 g sample mass of raw sugar based samples, 0.5 g sample mass of molasses based samples and an extraction mixture of concentrated HNO3-H2O2, in 25 mL of solvent. Analytical results obtained for the two metals by ultrasound assisted pseudo-digestion and conventional wet digestion methods showed a good agreement. This method reduces the time required for all treatments (heating to dryness, cooling and separation) in comparison with conventional wet digestion method. The accuracy of the method was tested by comparing the obtained results with that of conventional wet digestion method.   相似文献   

2.
Multielemental instrumental neutron activation (INAA), inductively coupled plasmaatomic emission spectrometric (ICP-AES) and atomic absorption spectrophotometric (AAS) analyses are utilized for the determination of Ag, Al, As, Au, Ba, Be, Br, Ca, Cd, Ce, Cl, Co, Cr, Cu, Eu, Fe, Ga, Hf, K, La, Li, Lu, Mg, Mn, Na, Nb, Ni, P. Pb, Sb, Sc, Se, Sm, Sn, Sr, Ta, Th, Ti, U, V, W and Zn in sugar cane plant, raw juice, juice in different stages, syrup, deposits, molasses, A, B and C sugar, refinery 1 and 2 sugar, and in soil samples picked up from the immediate vicinity of the cane plant roots at surface, 30 and 60 cm depth.  相似文献   

3.
Instrumental neutron activation analysis (INAA) have been used to determine As, Br, Hg, Sb and Se in combination with atomic absorption spectrometry (AAS) as a complementary technique for the quantification of Cd and Pb in jaggery, brown sugar, white sugar and molasses. All sugar cane products were collected from the local sugar cane industry of Pakistan. The highest concentration of these potentially toxic elements was quantified in molasses; however, molasses together with jaggery, brown sugar and white sugar contains trace amounts of all of these elements. Due to very low concentration of Cd it could only be detected in molasses. To evaluate the percentage contribution of these elements in the sugar cane products to the weekly recommended values, intakes on weekly consumption of 100 g of each item have also been calculated which follow the pattern Br>Se>Pb>Hg>As>Sb. The elevated Br contents may be attributed to the use of Br-containing chemicals for fumigation; however, these contents are well within the tolerance levels. The estimated weekly intake of all toxic elements is very low indicating that sugar cane products can be safely ingested as part of the diets.  相似文献   

4.
A method to improve the detection of cane or corn sugar addition to fruit juices has been developed. This involves the isolation of the individual sugars and measurement of their carbon isotope ratios. Using the Isotopic Relations of Individual Sugars approach, the additions of cane sucrose or cane invert as low as 4% of the total sugars can be detected in orange juice. This method offers a significant improvement over the conventional carbon isotopic method that has a detection limit of about 10%.  相似文献   

5.
An evaluation of the most commonly used HPLC system (reversed phase octadecyl sillica gel) was undertaken in order to determine the level of certain carbohydrates in molasses produced in the refining of sugar beet. Chromatographic parameters and purification operations prior to analysis are discussed in order to develop an analytical method permitting automation of sugar determination. A Zorbax ODS column (250 × 9.4 mm), water elution, and light scattering detection allow easy determination of glucose + fructose, sucrose, and raffinose in molasses using an internal standard (maltose).  相似文献   

6.
Abstract

An HPLC Group-Type Separation was developed for the analysis of the liquefaction product of sugar cane wood fibers (bagasse). First, a liquid-liquid extraction technique was applied to separate the highly polar and polymerized aqueous fraction from the less polar organic fraction. This last fraction was then separated by HPLC into four classification groups: three hydrocarbons (saturates, olefins and aromatics) and a combination of polar compounds.

The application of these extraction and separation methods to the analysis of Brazilian sugar cane residue liquefaction products was very promising since the major group present in the extract is the aromatic hydrocarbons, suggesting its potential use as chemical feedstock, as well as a possible renewable source of energy. In addition, the method generates discrete and “clean” fractions for further detailed characterization when desired.  相似文献   

7.
《Analytical letters》2012,45(7-8):581-590
Abstract

NMR analytical procedures are described for the qualitative and quantitative determination of amygdalin. The spectrum is very specific for amygdalin, particularly the sugar region. The optical nature may be conveniently ascertained from the chemical shifts of the aglycone methine hydrogens and the relative optical purity determined by comparing the corresponding peak areas. Satisfactory analyses of amygdalin-containing tablets have been carried out with a precision of 1.2% and accuracy of less than 1%.  相似文献   

8.
The concentration of 18 elements in different cane sugar products, i.e., cane sugar plants, crude and syrup juices, molasses, and the end products of the consumer sugar, were analyzed and processed. The samples were collected from five citics, i.e., Kom Ombo, Edfu, Armant, Deshna and Naga Hammady in Upper Egypt where the main Egyptian sugar industry factories are located. INAA was applied for the determination of Al, Ca, Cl, Co, Cr, Fe, Mg, Mn, Na and Sc, while Cu, Li, P, Sn, V and Zn were determined by ICP-AES and Pb and As were determined by AAS. These three analytical methods were applied to optimize the sensitivity and the accuracy of the measurements in order to provide a sound basis for the obtention of reliable clustering results.  相似文献   

9.
Sucrose is an attractive molecule for chemistry because it is pure, abundant, inexpensive, and produced from renewable sources. Amoung its derivatives, sucrose esters are valuable targets for the chemical valorization of sugar, either as polymerizable derivatives, surfactants, or non-caloric fat substitutes.2 But although such potential commercially attractive sucrose derived molecules can be targeted, methods consistent with low-cost sucrouse diversification have still to be found. The issue of the solvent being critical, we have been interested in evaluating water as a possible solvent for some transformations of sucrose, and we report herein some preliminary results on the esterification of this sugar in basic aqueous medium.

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10.

This study describes a pioneering industrial-scale experience by Tobasa in ethanol production from the amylaceous flour obtained by mechanical processing of the babassu mesocarp. Technical aspects related to enzymatic and fermentation processes, as well as overall economical aspects, are discussed. When produced in a small-size industrial plant (5000 L/d), babassu ethanol has a final cost of about $218/m3. The impact of raw materials, production, and processing (enzymes, steam, energy, and so on) on the final product cost is also presented. Babassu coconut ethanol can be produced at low cost, compared with traditional starchy raw materials or sugar cane. The net profitability of ethanol production is about 40% for babassu coconut and just 10% for sugar cane. If the estimated renewable babassu resources were entirely industrially used, 1 billion L/yr of ethanol could be produced, which would roughly correspond to 8% of the current Brazilian ethanol production.

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11.
The effects of feeding bees artificial sugars and/or proteins on the sugar compositions and 13C isotopic measurements of royal jellies (RJs) were evaluated. The sugars fed to the bees were two C4 sugars (cane sugar and maize hydrolysate), two C3 sugars (sugar beet, cereal starch hydrolysate), and honey. The proteins fed to them were pollen, soybean, and yeast powder proteins. To evaluate the influence of the sugar and/or protein feeding over time, samples were collected during six consecutive harvests. 13C isotopic ratio measurements of natural RJs gave values of around −25 ‰, which were also seen for RJs obtained when the bees were fed honey or C3 sugars. However, the RJs obtained when the bees were fed cane sugar or corn hydrolysate (regardless of whether they were also fed proteins) gave values of up to −17 ‰. Sugar content analysis revealed that the composition of maltose, maltotriose, sucrose, and erlose varied significantly over time in accordance with the composition of the syrup fed to the bees. When corn and cereal starch hydrolysates were fed to the bees, the maltose and maltotriose contents of the RJs increased up to 5.0 and 1.3 %, respectively, compared to the levels seen in authentic samples (i.e., samples obtained when the bees were fed natural food: honey and pollen) that were inferior to 0.2% and not detected, respectively. The sucrose and erlose contents of natural RJs were around 0.2 %, whereas those in RJs obtained when the bees were fed cane or beet sugar were as much as 4.0 and 1.3 %, respectively. The combination of sugar analysis and 13C isotopic ratio measurements represents a very efficient analytical methodology for detecting (from early harvests onward) the use of C4 and C3 artificial sugars in the production of RJ.  相似文献   

12.
《Analytical letters》2012,45(13):2411-2419
Abstract

A flow injection piezoelectric procedure is proposed for the determination of brix (total solids dissolved) in the alcoholic fermentation process. A piezoelectric Perspex cell was constructed to fit one of the gold electrodes of a 10 MHz crystal and this sensor was adapted to a flow injection system. The analytical curve is linear over the brix range from 0.5 to 20.0% with a detection limit of 0.3%. Seventy results can be obtained per hour and the relative standard deviation was less than 1.45% for a solution containing 6% of brix (n=15). Applications of this method for the determination of brix in sugar cane juice and in an alcoholic fermentation bench show satisfactory results in comparison with refractometric and densimetric methods, respectively.  相似文献   

13.
Abstract

Sugar losses result when sucrose in highly concentrated solution degrades under heat and other stresses in the factory and refinery and in manufacture of sugar containing products. Impurities such as salts, can increase the thermal degradation rate of sucrose under processing conditions, although literature sources conflict on the extent,2,3,4,5 and the mechanism of action has still to be ascertained.  相似文献   

14.
The possibility of using two by-products of the sugar cane industry, molasses and bagasse steam explosion liquor (SEL), for lignin peroxidase (LiP) production by Phanerochaete chrysosporium was investigated. For comparison, the fungus was initially cultivated in synthetic media containing either glucose, sucrose, xylose, or xylan as sole carbon sources. The effect of veratryl alcohol (VA) was also investigated in relation to the enzyme activity levels. Results showed that sucrose was not metabolized by this fungus, which precluded the use of molasses as a carbon source. Glucose, xylose, and xylan promoted equivalent cell growth. Enzyme levels in the absence of VA were lower than 28 UI/L and in the presence of VA reached 109 IU/L with glucose and 85 IU/L with xylose or xylan. SEL was adequate for P. chrysosporium LiP production as LiP activity reached 90 IU/L. When VA was added to this medium, enzyme concentration increased to 155 IU/L.  相似文献   

15.
The use of recovered paper and paper manufacturing wastes are a potentially large, concentrated, and convenient raw material for ethanol production via enzyme hydrolysis and fermentation. However, many previous studies in the area have investigated impractically high enzyme charges. In this research, low dosages of enzymes on copy paper (CP) were investigated for the conditions of 5% consistency (w/v) and 50 °C for 48 h. The removal of inorganic filler (mainly calcium carbonate) by washing prior to hydrolysis led to higher sugar yields than the unwashed CP as well as CP acidified to remove the ash. Enzyme adsorption measurement showed that both acid-soluble ash and acid-insoluble ash adsorb enzymes with a greater affinity than fibers. Drying of the fibers (termed hornification) decreased the efficiency of enzyme hydrolysis, confirming previous results. The mechanical refining at 10% consistency in a laboratory refining mill of previously dried fibers improved the sugar recovery to similar or higher levels as never-dried fibers. By plotting water retention value (WRV) versus corresponding sugar recovery, it was shown that WRV is more useful at low enzyme charges reflecting the use of refining and the reversal of hornification. For de-ashed and refined copy paper, the sugar recovery was determined to be 82% and 97% with enzyme dosages of 4 and 8 Filter Paper Unit (FPU)/g oven-dried (OD) substrate.  相似文献   

16.
甲醛测定方法的进展概述   总被引:2,自引:0,他引:2  
甲醛是一种重要的化工原料,因其价格低、用途广、易制备等原因被广泛应用到化工、建材、食品、材料、纺织等行业。但甲醛毒性较高,对人体健康、空气质量都有着严重的影响,其污染问题愈来愈受到人们的关注。因此,甲醛的及时准确检测显得尤为重要。该文综述了几种常用的甲醛测定方法。  相似文献   

17.
Some sugars, specifically white beet sugar and raw cane sugars, possess off-flavors and off-odors. Although not necessarily the source, the presence of short-chain fatty acids serves as an indicator of an off-odor problem in sugar. Solid-phase microextraction (SPME) is used to collect the volatile compounds from the headspace of sugar. The temperature, moisture, and type of SPME fiber are varied to optimize recovery. Sugars analyzed in the absence of water using an incubation temperature of 70 degrees C with a divinylbenzene-carboxen-polydimethylsiloxane fiber yield the most reproducible results. Data from depletion analyses report a recovery level of 38% for the first injection. The semiquantitative analysis of butyric acid is accomplished using injected standards to develop a calibration curve.  相似文献   

18.
ABSTRACT

The degradation of sucrose can decrease sucrose yield, reduce the efficiency of sugar factory and refinery processes, and effect end product quality. Characterization of sucrose degradation under modeled industrial processing conditions will underpin further technological improvements. Effects of constant reaction pH on sucrose degradation were investigated using simulated industrial model systems (100 °C; 65 °Brix [% dissolved solids]; N2; 0.05-3 mol NaOH titrant; 8 h), with the use of an autotitrator. Reaction pH values ranged from 4.40 to 10.45. Polarimetry and ion chromatography with integrated pulsed amperometric detection (IC-IPAD) were used to quantify sucrose degradation and first-order reaction constants were calculated. Minimum sucrose degradation occurred between pH 6.45 - 8.50, with minimum color formation between pH's 4.40 - 7.00. Polarimetry, often used in U.S. sugar factories and refineries to monitor chemical sucrose losses, was shown not to be viable to measure sucrose degradation under alkaline conditions, because of the formation of fructose degradation products with an overall positive optical rotation. For comparison, fructose and glucose (80 °C; 65 °Brix; N2; 3 mol NaOH; 2 h) were also degraded at constant pH 8.3 conditions. For sucrose, fructose, and glucose, formation of organic acids on degradation was concomitant with color formation, indicating they are probably produced from similar reaction pathways. For the glucose and fructose degradation reactions, color and organic acid formation also were highly correlated (R2>0.966) with changes in optical rotation values, confirming that these compounds are formed from similar reaction pathways.  相似文献   

19.
Kendrick Mass Mapping of complex sample compositions, via data derived by Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) at 1 000 000 resolution, is becoming more common. The Orbitrap mass spectrometer (Fourier Transform Axially Harmonic Orbital Trapping) also uses FT methods and indirect detection, though operating at a maximum resolution of 100 000. We define the more general case of Normalized Mass Mapping to any repeating oligomer unit (e.g., C3H6O2) and apply it to Orbitrap‐based mapping of a complex polyglycerol ester, 'green' raw material. Mass measurement errors showed sub‐ppm precision and accuracy in many cases, parameters that are critical to obtaining well‐defined maps. Map‐derived, raw‐material‐characterization parameters such as iodine value are compared with wet‐chemical results and show reasonable agreement for our purposes. The methodology appears applicable to raw material control and eliminates wet chemical methods. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

20.

A simple and effective method using ion chromatography was developed for the simultaneous determination of five monosaccharides (arabinose, glucose, fructose, xylose, and ribose) and two disaccharides (sucrose and lactose) in raw sugar samples. The separation was performed on a CarboPac PA 10 column using the gradient elution of sodium hydroxide and water as the mobile phase. Monosaccharides and disaccharides were detected by an integrated pulsed amperometric detection (IPAD) using gold working electrode. Acid hydrolysis was used for sample preparation before the analysis of glucose and fructose. All the studied sugars showed good linear ranges within 0.5–100 µg mL−1 with the correlation coefficients higher than 0.997. The limits of detection were all less than 0.5 µg mL−1. The RSDs of the method were less than 10 %. The recoveries of the sugars that spiked in raw sugar samples ranged from 96.1 to 102.4 %. The method was successfully applied for the analysis of sugars in raw sugar samples. Sucrose is the major constituent found in the samples at 97 %.

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