共查询到20条相似文献,搜索用时 31 毫秒
1.
A collaborative study of the carbon-13 isotope ratio mass spectrometry (13C-IRMS) method based on fermentation ethanol for detecting some sugar additions in fruit juices and maple syrup is reported. This method is complementary to the site-specific natural isotope fractionation by nuclear magnetic resonance (SNIF-NMR) method for detecting added beet sugar in the same products (AOAC Official Methods 995.17 and 2000.19), and uses the same initial steps to recover pure ethanol. The fruit juices or maple syrups are completely fermented with yeast, and the alcohol is distilled with a quantitative yield (>96%). The carbon-13 deviation (delta13C) of ethanol is then determined by IRMS. This parameter becomes less negative when exogenous sugar derived from plants exhibiting a C4 metabolism (e.g., corn or cane) is added to a juice obtained from plants exhibiting a C3 metabolism (most common fruits except pineapple) or to maple syrup. Conversely, the delta13C of ethanol becomes more negative when exogenous sugar derived from C3 plants (e.g., beet, wheat, rice) is added to pineapple products. Twelve laboratories analyzed 2 materials (orange juice and pure cane sugar) in blind duplicate and 4 sugar-adulterated materials (orange juice, maple syrup, pineapple juice, and apple juice) as Youden pairs. The precision of that method for measuring delta13C was similar to that of other methods applied to wine ethanol or extracted sugars in juices. The within-laboratory (Sr) values ranged from 0.06 to 0.16%o (r = 0.17 to 0.46 percent per thousand), and the among-laboratories (SR) values ranged from 0.17 to 0.26 percent per thousand (R = 0.49 to 0.73 percent per thousand). The Study Directors recommend that the method be adopted as First Action by AOAC INTERNATIONAL. 相似文献
2.
Abstract In the cane sugar industry the purchase price of raw cane sugar, the product of sugar cane processing, is determined by polarimetric measurement of sucrose content in raw sugar solutions, expressed as Pol. Raw sugar generally contains more than 96% sucrose, but also contains other saccharides and non-sugars which can contribute to Pol. Dextrans, one class of polysaccharides often found in raw sugar, effect an increase in Pol and interfere with subsequent refining. The U.S. sugar refining industry can impose a penalty on the raw sugar purchase price for high dextran content. While there are several wet chemical methods for the determination of dextran in raw sugar, the results of these analyses are rarely in agreement. The existing wet chemical methods for the determination of dextran in raw cane sugar are reviewed and the results of these wet chemical analyses are compared with the results obtained from the physical measurement of dextran in raw sugar by 1H NMR spectroscopy. 相似文献
3.
S. Waheed S. Rahman K. P. Gill 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(3):725-731
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.
Combination of sugar analysis and stable isotope ratio mass spectrometry to detect the use of artificial sugars in royal jelly production 总被引:1,自引:0,他引:1
Marine Wytrychowski Ga?lle Daniele Hervé Casabianca 《Analytical and bioanalytical chemistry》2012,403(5):1451-1456
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
5.
Martin YL 《Journal of AOAC International》2001,84(5):1509-1521
Results of a collaborative study are reported for the detection of added beet or cane sugar in maple syrup by the site-specific natural isotope fractionation-nuclear magnetic resonance (SNIF-NMR) method. The method is based on the fact that the deuterium content at specific positions of the sugar molecules is different in maple syrup from that in beet or cane sugar. The syrup is diluted with pure water and fermented; the alcohol is distilled with a quantitative yield and analyzed with a high-field NMR spectrometer fitted with a deuterium probe and fluorine lock. The proportion of ethanol molecules monodeuterated at the methyl site is recorded. This parameter (D/H)I is decreased when beet sugar is added and increased when cane sugar is added to the maple syrup. The precision of the method for measuring (D/H)I was found to be in good agreement with the values already published for the application of this method to fruit juice concentrates (AOAC Official Method 995.17). An excellent correlation was found between the percentage of added beet sugar and the (D/H)I isotopic ratio measured in this collaborative study. Consequently, all samples in which exogenous sugars were added were found to have a (D/H)I isotopic ratio significantly different from the normal value for an authentic maple syrup. By extension of what is known about plants having the C4 cycle, the method can be applied to corn sweeteners as well as to cane sugar. One limitation of the method is its reduced sensitivity when applied to specific blends of beet and cane sugars or corn sweeteners. In such case, the C13 ratio measurement (see AOAC Official Method 984.23, Corn Syrup and Cane Sugar in Maple Syrup) may be used in conjunction. 相似文献
6.
《液相色谱法及相关技术杂志》2012,35(1):217-228
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.
Kakali Mukherjee Rumpa Saha Aniruddha Ghosh Sumanta K. Ghosh Pradip K. Maji Bidyut Saha 《Research on Chemical Intermediates》2014,40(4):1727-1734
Agricultural products and by-products are now widely used for removal of hexavalent chromium from waste water. This option is more efficient and less expensive than conventional physicochemical treatments. The purpose of this study was reduction of carcinogenic hexavalent chromium to non-toxic trivalent chromium by use of aqueous extracts of sugar cane bagasse, which contains a variety of reducing components, for example sugar. The rate of this process is accelerated by use of surfactant as catalyst. 相似文献
8.
Yuling Yang Tingting Deng Weifeng Cao Fei Shen Sijia Liu Jing Zhang Xinquan Liang Yinhua Wan 《Molecules (Basel, Switzerland)》2022,27(3)
Firstly, 2,3-butanediol (2,3-BDO) is a chemical platform used in several applications. However, the pathogenic nature of its producers and the expensive feedstocks used limit its scale production. In this study, cane molasses was used for 2,3-BDO production by a nonpathogenic Clostridium ljungdahlii. It was found that cane molasses alone, without the addition of other ingredients, was favorable for use as the culture medium for 2,3-BDO production. Compared with the control (i.e., the modified DSMZ 879 medium), the differential genes are mainly involved in the pathways of carbohydrate metabolism, membrane transport, and amino acid metabolism in the case of the cane molasses alone. However, when cane molasses alone was used, cell growth was significantly inhibited by KCl in cane molasses. Similarly, a high concentration of sugars (i.e., above 35 g/L) can inhibit cell growth and 2,3-BDO production. More seriously, 2,3-BDO production was inhibited by itself. As a result, cane molasses alone with an initial 35 g/L total sugars was suitable for 2,3-BDO production in batch culture. Finally, an integrated fermentation and membrane separation process was developed to maintain high 2,3-BDO productivity of 0.46 g·L−1·h−1. Meanwhile, the varied fouling mechanism indicated that the fermentation properties changed significantly, especially for the cell properties. Therefore, the integrated fermentation and membrane separation process was favorable for 2,3-BDO production by C. ljungdahlii using cane molasses. 相似文献
9.
Ethanol/water pulps from sugar cane straw and their biobleaching with xylanase from Bacillus pumilus
The influence of independent variables (temperature and time) on the cooking of sugar cane straw with ethanol/water mixtures was studied to determine operating conditions that obtain pulp with high cellulose contents and a low lignin content. An experimental 2(2) design was applied for temperatures of 185 and 215 degrees C, and time of 1 and 2.5 h with the ethanol/water mixture concentration and constant straw-to-solvent ratio. The system was scaled-up at 200 degrees C cooking temperature for 2 h with 50% ethanol-water concentration, and 1:10 (w/v) straw-to-solvent ratio to obtain a pulp with 3.14 cP viscosity, 58.09 kappa-number, and the chemical composition of the pulps were 3.2% pentosan and 31.5% lignin. Xylanase from Bacillus pumilus was then applied at a loading of 5-150 IU/g dry pulp in the sugar cane straw ethanol/water pulp at 50 degrees C for 2 and 20 h. To ethanol/water pulps, the best enzyme dosage was found to be 20 IU/g dry pulp at 20 h, and a high enzyme dosage of 150 IU/g dry pulp did not decrease the kappa-number of the pulp. 相似文献
10.
H. Yonezawa K. Shikano T. Shigematsu 《Journal of Radioanalytical and Nuclear Chemistry》1997,216(2):289-292
Brazil has become the largest producer of biomass ethanol derived from sugar cane. The industrial production is based on the fermentation of sugar cane juice by yeast, inside of large volume vats, in a fed-batch process that recycles yeast cells. To study the dynamics of chemical elements in each operating cycle, five stages of the fementation process were considered: must, yeast suspension, wine, non-yeast wine and yeast cream. For this, a mass balance of the terrigenous elements, Ce, Co, Cs, Eu, Fe, Hf, La, Na, Sc, Sm, and Th, and the sugar cane plant elements, Br, K, Rb, and Zn, were established in fementation vats of an industrial scale unit, with sampling undertaken during different climatic conditions (dry and rainy periods). A similar distribution of the sugar cane characteristics elements was found for the stages analysed, while for the terrigenous elements a trend of accumulation in the yeast cream was observed. Preferential absorption of Br, K, Rb, and Zn by yeast cells was indicated by the smaller concentrations observed in yeast suspension than in yeast cream. 相似文献
11.
气相色谱检测甘蔗中乐果和特丁磷的残留量 总被引:1,自引:0,他引:1
甘蔗经加速溶剂萃取仪萃取,应用气相色谱仪定量法检测乐果和特丁磷,建立了定量检测甘蔗中乐果和特丁磷的快速、准确、高灵敏度的方法。经方法学验证,该方法对乐果最低检出限(LOD)为0.01 mg/kg,特丁磷LOD为0.05 mg/kg。乐果和特丁磷在1.0~100.0μg/mL的线性范围内,相关系数r>0.999 9。乐果回收率为91.5%~99.6%,相对标准偏差(RSD)为1.9%~3.2%,特丁磷回收率为81.0%~93.2%,RSD为2.0%~3.5%。结果表明,该检测方法灵敏度高、操作简单、定量准确、测定浓度范围广,是甘蔗样品中乐果和特丁磷含量检测的理想方法。 相似文献
12.
An interlaboratory comparison by 13C-isotope ratio mass spectrometry was organised by working group No. 1 of the European Commission of Standardisation (CEN/TC 174) in order to define the repeatability (r) and the reproducibility (R) of the 13C determination in sugars and pulp, isolated from the same fruit juice. Six unlabelled juices were analysed in 19 laboratories in the European Union, Australia and the USA. Three samples were authentic juices (orange, grapefruit, pineapple) and the remaining samples were the same juices with an addition of sugar at 15 g l−1 (orange, pineapple) or 11.8 g l−1 (grapefruit). The sugar was prepared by mixing equal amounts of beet and cane sucroses. The different laboratories used the same experimental protocol under different conditions (operator, conversion system for CO2 preparation, mass spectrometer). The results for the sugars (r = 0.27%., R = 0.82%.) were comparable to those from an earlier ring test (r = 0.30%., R = 0.70%.), while the results for the pulp presented higher interlaboratory variability (r = 0.38%., R = 1.89%.) possibly due to experimental difficulties. Nevertheless, the RSDR for free sugars ranged 0.9–3.2% and for pulp, 0.9–9.3%. On the basis of the Horwitz equation and taking account of the concentration of the isotopes measured, an RSDR of 7–8% might have been expected. The experimentally determined RSDR values were less than twice the theoretically expected values, which is a criterion of an acceptable method. The results were therefore considered to be acceptable by specialists in the field of isotopic analysis, and the method applied was found to improve the sensitivity of the 13C determination for the detection of sugar addition in fruit juices. 相似文献
13.
O. Dáz Rizo J. Griffith Martínez 《Journal of Radioanalytical and Nuclear Chemistry》1996,213(5):377-384
This paper shows the result of soil-plant relation in samples from Cuban sugar canes of different soil types and cane varieties, using INAA from a thermal reactor. The behavior of minor and trace elements in sugar cane leaves is unifor and independent of sugar cane variety of type of soil. The soil-plant relation shows four principal groups of micro elements, according to their absorption by the plant. 相似文献
14.
The physico-chemical properties of biochars from the vacuum pyrolysis of black wattle and vineyard annual prunings were investigated for their potential as soil amendments and compared to biochar from sugar cane bagasse. Biochar from sugar cane bagasse seems to be a promising sorbent and soil conditioner due to its high surface area, high surface acidity and microporous structure. This biochar can be applied to a wide pH range of soils for enhancing nutrient and water retention. On the other hand, the biochars from black wattle and vineyard possessing high concentrations of aromatic carbon, nutrients, and alkalinity are potential soil amendment agents. Black wattle biochar is more beneficial compared to biochar from vineyard due to its higher surface area, microporosity and cation exchange capacity. Therefore, this study recommends the utilization of biochars from black wattle as soil amendment agents especially in subtropical regions. 相似文献
15.
R.E. Cochran N. DongariH. Jeong J. Beránek S. Haddadi J. Shipp A. Kubátová 《Analytica chimica acta》2012
A sensitive method has been developed for the trace analysis of PAHs and their oxidation products (i.e., nitro-, oxy-, and hydroxy-PAHs) in air particulate matter (PM). Following PM extraction, PAHs, nitro-, oxy-, and hydroxy-PAHs were fractionated using solid phase extraction (SPE) based on their polarities. Gas chromatography–mass spectrometry (GC–MS) conditions were optimized, addressing injection (i.e., splitless time), negative-ion chemical ionization (NICI) parameters, i.e., source temperature and methane flow rate, and MS scanning conditions. Each class of PAH oxidation products was then analyzed using the sample preparation and appropriate ionization conditions (e.g., nitro-PAHs exhibited the greatest sensitivity when analyzed with NICI–MS while hydroxy-PAHs required chemical derivatization prior to GC–MS analysis). The analyses were performed in selected-ion-total-ion (SITI) mode, combining the increased sensitivity of selected-ion monitoring (SIM) with the identification advantages of total-ion current (TIC). The instrumental LODs determined were 6–34 pg for PAHs, 5–36 pg for oxy-PAHs, and 1–21 pg for derivatized hydroxy-PAHs using electron ionization (GC-EI-MS). NICI–MS was found to be a useful tool for confirming the tentative identification of oxy-PAHs. For nitro-PAHs, LODs were 1–10 pg using negative-ion chemical ionization (GC-NICI-MS). The developed method was successfully applied to two types of real-world PM samples, diesel exhaust standard reference material (SRM 2975) and wood smoke PM. 相似文献
16.
Fernando M. Lanas Janete H. Y. Vilegas Srgio Martins Elaine A. F. Gobato 《Journal of separation science》1994,17(4):237-244
An overview is presented of the analytical approaches developed by our research group over the last ten years for analysis of alternative fuel, both biomass and fossil. The alternative fuels are analyzed successively by PLC-8 (preparative liquid chromatography–group-type) fractionation and high resolution gas chromatography. Some of the possibilities for fractionation and characterization of alternative fuels are herein exemplified with sugar cane bagasse pyrolysis products. 相似文献
17.
18.
Joselito P. Quirino 《Chromatographia》2010,72(5-6):503-510
Capillary zone electrophoresis (CZE) with electrospray ionization (ESI) mass spectrometry (MS) was used to study borate (B?1) and sugar (L) complexes (L x B?1). Boric acid was adjusted to pH 10 with ammonium hydroxide to create an ESI-MS compatible CZE background electrolyte. We show for the first time that the electrophoretic peaks for each injected sugar contained both the substrates (i.e., sugar and/or multimers) and products (i.e., L x B?1). The effects of sheath liquid, temperature, and borate concentration were studied. The molecular mass information obtained from the ESI-MS provided new evidence on the mechanisms of borate-sugar complexation. Direct infusion ESI-MS and CZE-ESI-MS experiments strongly suggest that the formation of L x B?1 was from the direct reaction of a sugar or sugar multimer (L x ) and B?1. Larger L x B?1, where x > 2 were observed. Separation in the CZE dimension allows for the simultaneous analysis of a sugar mixture and simplified the ESI-MS analysis of sugars of the same molecular mass. The increase in sugar electrophoretic mobility caused by the increase in borate concentration was discussed in terms of the formation of L x B?1 complexes. In addition, the separation of five nucleosides by CZE using a borate electrolyte and detection using ESI-MS is demonstrated. 相似文献
19.
20.
David Jirovsky Petr Bedná? Renáta Myjavcová Zdenka Barto?ová Jana Skopalová Michaela Tvrdoňová Karel Lemr 《Monatshefte für Chemie / Chemical Monthly》2011,378(4):1211-1217