Viagens Celestiais: Da Apocalíptica à Literatura Hekhalot

Nogueira, Sebastiana Maria Silva

doi:10.15603/1807-8222/oracula.v7n12p267-285

Cited by 1 publication

(4 citation statements)

References 14 publications

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“…As their objective of analysis was edible oils, the anions of interest were slightly different from this study. Nogueira and Do Lago applied capillary electrophoresis in the determination of cations Ca 2+ , K + , Mg 2+ , and Na + , as well as anions SO 4 2– , PO 4 3– , formate, acetate, and propionate in biodiesel. On the other hand, Strömberg and Sahlin specifically targeted six short-chain VFAs by an ion exclusion chromatography method.…”

Section: Resultsmentioning

confidence: 99%

“…Sulfur, nitrogen and phosphorus in oil can exist in both inorganic and organic forms. 20 For instance, total phosphorus is composed of organic P (phosphatides) and inorganic P (phosphate), and the relative amount can vary considerably with types and sources of oilseeds and the pressure and temperature used in the extraction process. 21 The existing standards are for the total contents of these elements, without concern for their speciation.…”

Section: Introductionmentioning

confidence: 99%

“…These methods determine the total contents of P and S in a combusted form, sometimes after dilution with toxic solvent. , Various alternative methods are being studied for short chain VFAs, phosphorus and sulfur components. For example, Strömberg and Sahlin developed an ion exclusion chromatography method for 6 short chain fatty acids, whereas phosphorus in oil has been measured by colorimetric method, graphite furnace atomic absorption spectrometry, molecular absorption spectrophotometry, FIA spectrometry, capillary electrophoresis, and so froth. However, these methods usually involve sophisticated instrumentation or complicated sample pretreatment procedures like solvent extraction or emulsion, which could restrict their use in practice.…”

Section: Introductionmentioning

confidence: 99%

“…Another problem of measurement is the speciation of the elements. Sulfur, nitrogen and phosphorus in oil can exist in both inorganic and organic forms . For instance, total phosphorus is composed of organic P (phosphatides) and inorganic P (phosphate), and the relative amount can vary considerably with types and sources of oilseeds and the pressure and temperature used in the extraction process .…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous Determination of Seven Anions of Interest in Raw Jatropha curcas Oil by Ion Chromatography

et al. 2014

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Various ions are of interest to the quality of biodiesel feedstock and products. In this study, a simple and labor-saving analytical method was developed to directly and simultaneously measure seven anions of interest in oil, utilizing an ion chromatography system with function of sample matrix elimination. Various eluent profiles were explored and calibration curves were made to analyze 13 raw Jatropha curcas oils for their contents of formate, acetate, nitrite, nitrate, sulfite, sulfate and phosphate. A 23 min program was found to sufficiently separate all the ions, and linear correlation higher than 99% was achieved for all the ions except formate (98.6%). High diversity was found in both the presence and concentration range of these ions. Formate, nitrate, and phosphate were more prevalent among the ions tested, such that 12, 10, and 11 samples showed their presence, respectively. Nitrite was found in only two samples with the concentrations lower than 10 mg kg–1. Formate concentration ranged from 0 to over 3000 mg kg–1, and nitrate and phosphate showed ranges of 0 to 100 and 0 to 300 mg kg–1, respectively. Acetate was less common than formate, and its concentration was universally lower (0 to 500 mg kg–1). In addition, the occurrence of acetate and nitrite seemed to be correlated to that of formate and nitrate, respectively, whereas sulfite and sulfate showed mutual exclusion. This method showed reasonably good detection limits and reproducibility, that concentrations of around 0.2 mg L–1 can be detected in the organic samples, and in most cases the ratio of standard deviation to average was below 25%. However, for phosphate, the accuracy and reproducibility need further improvement, possibly by decreasing sample dilution ratio and optimizing eluent profile.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%