Quantitative Determination of Carbohydrates With Dreywood's Anthrone Reagent

Morris, Daniel L.

doi:10.1126/science.107.2775.254

Cited by 1,800 publications

(694 citation statements)

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“…19,20 Total organic carbon (TOC) was determined using a Shimadzu 5000A TOC analyzer. Hydrodynamic diameter of EPS was determined using the Zetasizer.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Influence of Extracellular Polymeric Substances on the Long-Term Fate, Dissolution, and Speciation of Copper-Based Nanoparticles

Adeleye

Conway

Pérez

et al. 2014

Environ. Sci. Technol.

210

217

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ABSTRACT:The influence of phytoplankton-derived soluble extracellular polymeric substances (EPS), pH, and ionic strength (IS) on the dissolution, speciation, and stability of nano-CuO, nano-Cu, and Kocide (a micron sized Cu(OH) 2 -based fungicide) was investigated over 90 days. EPS improved the stability of commercial copper-based nanoparticles (CBNPs) in most conditions, in addition to influencing their dissolution. The dissolution rate was pH 4 ≫ pH 7 > pH 11. The presence of EPS correlated with higher dissolved Cu at pH 7 and 11, and lower dissolved Cu at pH 4. More dissolution was observed at higher IS (NaCl) due to complexation with Cl − . Dissolution of nano-CuO at pH 7 increased from 0.93% after 90 days (without EPS) to 2.01% (with 5 mg-C EPS/L) at 10 mM IS. Nano-CuO dissolved even more (2.42%) when IS was increased to 100 mM NaCl (with EPS). The ratio of freeCu 2+ /total dissolved Cu decreased in the presence of EPS, or as pH and/or IS increased. On a Cu mass basis, Kocide had the highest dissolved and suspended Cu at pH 7. However, dissolution of nano-Cu resulted in a higher fraction of free Cu 2+ , which may make nano-Cu more toxic to pelagic organisms. ■ INTRODUCTIONGlobal production of copper-based nanoparticles (CBNPs) was estimated at ∼200 t/yr in 2010, and is increasing. 1 CBNPs have found use in cosmetics, pigments, paints and coatings, electronics, and pesticides. 2−4 These applications may lead to direct exposure of CBNPs to the environment due to normal use, product wear-and-tear, and/or end-of-life disposal. 1 Toxicity of CBNPs and composites to organisms has been demonstrated. 2,5−8 It is therefore important to understand the long-term fate and transformations of these materials in aquatic systems in order to predict exposure to at-risk organisms.Stability and dissolution of engineered nanoparticles (ENPs) depend on ionic strength (IS), pH, and natural organic material (NOM). 9−12 Rapid aggregation of nano-Cu was reported in freshwater by Griffitt et al. 5 The authors also found that less than 0.1% of the nano-Cu dissolved in 48 h in the freshwater media used (pH 8.2). 98% dissolution of nano-Cu was however reported at pH 6 in "uterine-fluid" after a week, 13 demonstrating the importance of pH and media composition on CBNPs' dissolution. Mudunkotuwa and co-workers 14 reported increased dissolution of aged and new CBNPs in the presence of organic acids. Similarly, Worthington et al. 15 showed that the chitosan improved stability and dissolution of nano-Cu. To our knowledge, no studies have previously investigated the effects of naturally occurring NOM such as extracellular polymeric substances (EPS) on the stability and dissolution of CBNPs. EPS are synthesized by microorganisms, which are abundant in natural aquatic systems. EPS are mainly composed of polysaccharides, proteins, nucleic acids, and other polymers; and their composition may vary spatially and temporally even within the same species. 16 EPS may interact with ENPs, thus affecting their fate and transformation. 17 Additional...

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“…19,20 Total organic carbon (TOC) was determined using a Shimadzu 5000A TOC analyzer. Hydrodynamic diameter of EPS was determined using the Zetasizer.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Influence of Extracellular Polymeric Substances on the Long-Term Fate, Dissolution, and Speciation of Copper-Based Nanoparticles

Adeleye

Conway

Pérez

et al. 2014

Environ. Sci. Technol.

210

217

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“…Após a secagem, esta amostra foi diluída em 0,1 mL de KOH a 30% e depois mantida a 100ºC por 10 min., para degradação da frutose livre; após este período, a concentração de sacarose foi determinada por espectrofotometria, empregando o método da Antrona (MORRIS, 1948). A concentração de frutose foi estimada a partir da diferença entre os açúcares totais e o somatório das concentrações de glicose e sacarose.…”

Section: Análise De Açúcares No Néctarunclassified

Influência de abelhas africanizadas na concentração de açúcares no néctar de soja (Glycine max L. Merrill) var. Coodetec 207

Alves

Toledo²,

Oliveira

et al. 2010

Acta Sci. Anim. Sci.

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RESUMO.O objetivo foi avaliar a concentração de açúcares no néctar de soja (Glycine max L. Merrill) em áreas com ou sem a presença de abelhas Apis mellifera L. Foi utilizada a variedade Codetec 207 em quatro tratamentos: área de 24 m 2 coberta com colônia de abelhas africanizadas em seu interior; área semicoberta com livre acesso para insetos visitantes; área livre e área coberta sem abelhas. As flores foram coletadas durante três dias, a cada 2h. e a concentração dos açúcares totais por flor foi determinada por espectrofotometria. A área coberta com abelha apresentou maior concentração de açúcares totais em relação à área coberta sem abelhas e livre, contudo, a concentração de açúcares totais na área livre não diferiu da concentração observada na área coberta sem abelhas. Houve redução na concentração média de sacarose na área livre, diferindo das concentrações nas demais áreas. A concentração média de glicose não diferiu entre os tratamentos, enquanto que a de frutose não apresentou diferença entre as áreas cobertas com abelhas, semicoberta e livre. A variedade Codetec 207 da soja apresentou maior concentração total de açúcares e de frutose nas áreas cobertas com abelhas. Contudo, a presença de Apis mellifera não interferiu nesta concentração de açúcares no néctar das flores de soja desta variedade.Palavras-chave: concentração de açúcares, néctar, polinização, soja.ABSTRACT. Influence of Africanized honeybees on sugar concentration in the nectar of soybean (Glycine max L. Merrill) var. Codetec 207. This research was carried out to evaluate the sugar concentration in soybean nectar in areas with Africanized honeybee colonies. The var. Codetec 207 was used in four treatments: 24 m 2 covered area with Africanized honeybee colony inside, semi-covered area for free insect visitation, uncovered area, and covered area without insect visitation. Flowers were harvested for three days at two-hour intervals, and the total sugar concentration per flower was determined by spectrophotometry. The covered area with Africanized honeybee colony presented higher sugar concentration than the covered area without insect visitation; however, the sugar concentration in the uncovered area did not differ from the concentration observed in the covered area without honeybees. There was a reduction in the average of sucrose concentration in the uncovered area, different from concentrations in other areas. The glucose concentration did not differ among treatments, whereas fructose did not differ between the areas covered with honeybees, semi-covered and uncovered area. The soybean var. Codetec 207 presented higher total sugar and fructose concentrations in the covered area with honeybee colonies. However, the presence of Apis mellifera did not influence this sugar concentration in the nectar of soybean flowers of this variety.

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“…The soluble sugars were extracted with 80 % ethanol (v/v) following the methods of Omafuvbe et al (2004). The total soluble sugar was determined by the anthrone reagent method of Morris (1948) and reducing sugar was determined by the calorimetric method (Somogyi 1945) using standard curve of glucose.…”

Section: Determination Of Sugarsmentioning

confidence: 99%

Production of local dadawa seasoning and condiment from <i>Acacia nilotica</i> (linn) seeds.

Yabaya¹

2010

Science World Journal

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Dadawa was produced in the laboratory by fermenting Acacia nilotica LINN Rico 1994 seeds with Bacillus subtilis(Ehrenberg 1835) Cohn 1872 and analysed for proximate content, temperature and pH. There was 5 % increase in ash and moisture content and a corresponding reduction in crude fibre. The crude protein and carbohydrates increased by 3.81 % and 14.81 % respectively while the pH rose from 5.09 at the beginning of the fermentation to 8.43 at the end. With the increase in the time of fermentation, the microbial growth was rapid, increasing from 10.05-56.87 log10 c.f.u.g -1 resulting in a rise in the fermentation temperature from 27.5 o C-31.7 o C after 48 hours which dropped thereafter to 27.3 o C at the end of the process. The total soluble sugar decreased from 27.21-14.45 mg.g -1 while the reducing sugar increased from 2.18-10.23 mg.g -1 after 48 hours before reducing to 8.07 mg -1 on the 3 rd day. There was no significant difference (P<0.05) in the organoleptic attributes scored between the dadawa produced by fermenting Acacia nilotica seeds with Bacillus subtilis and that produced from locust beans

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Quantitative Determination of Carbohydrates With Dreywood's Anthrone Reagent

Cited by 1,800 publications

References 1 publication

Influence of Extracellular Polymeric Substances on the Long-Term Fate, Dissolution, and Speciation of Copper-Based Nanoparticles

Influence of Extracellular Polymeric Substances on the Long-Term Fate, Dissolution, and Speciation of Copper-Based Nanoparticles

Influência de abelhas africanizadas na concentração de açúcares no néctar de soja (Glycine max L. Merrill) var. Coodetec 207

Production of local dadawa seasoning and condiment from <i>Acacia nilotica</i> (linn) seeds.

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