Determination of Sulfur and Halogens

Peters, E. D.; Rounds, G. C.; Agazzi, E. J.

doi:10.1021/ac60064a026

Cited by 34 publications

(21 citation statements)

References 19 publications

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“…According to the pyrohydrolysis concept, chlorine release from the sample at high temperatures is thermodynamically possible in the presence of water vapour, where hydrochloric acid is formed. 12 However, in some studies 32,33 sample preparation was performed in the absence of water. In the present work, tests were carried out to evaluate the effect of water vapour on chlorine release.…”

Section: Influence Of Water Vapourmentioning

confidence: 99%

Heavy crude oil sample preparation by pyrohydrolysis for further chlorine determination

et al. 2011

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In this work, a method for chlorine determination in heavy crude oil using pyrohydrolysis for sample decomposition was developed. Chlorine was determined using ion chromatography (IC), inductively coupled plasma optical emission spectrometry (ICP OES) and inductively coupled plasma mass spectrometry. In this case an ICP-MS spectrometer equipped with a dynamic reaction cell (DRC-ICP-MS) was used. Heavy crude oil samples were homogenized and placed on a quartz holder, which was then introduced into the pyrohydrolysis apparatus. Nitric acid (0.2 mL) was used to assist the decomposition of the sample. Solutions with different concentrations of ammonium hydroxide were evaluated to collect the volatile chloride produced using pyrohydrolysis. A 0.75 mol L À1 ammonium hydroxide solution was chosen in view of the better accuracy achieved. Best precision and accuracy were obtained by heating the sample for 10 min up to 1000 C. The limits of quantification (LOQs, 10s) of chlorine measured by IC, ICP OES and DRC-ICP-MS were 4.5, 48 and 3.6 mg g À1 , respectively. A sample amount of 300 mg and final volume of 20 mL were taken into account to calculate the LOQs. The relative standard deviation (RSD) was lower than 5% (4 replicates). Accuracy was evaluated by analysis of certified reference material (NIST 1634c) and comparison with the results obtained using the ASTM D6470 method. In both cases the results obtained using pyrohydrolysis were in agreement. The proposed method was suitable for heavy crude oil decomposition and chlorine determination by IC, ICP OES and DRC-ICP-MS. Three samples per hour can be processed using a simple and low-cost pyrohydrolysis apparatus. The pyrohydrolysis procedure is easy to perform, which is very attractive for routine analysis of crude oil, a very complex matrix. According to the authors' knowledge this is the first application of pyrohydrolysis for heavy crude oil sample preparation.

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Section: Influence Of Water Vapourmentioning

confidence: 99%

Heavy crude oil sample preparation by pyrohydrolysis for further chlorine determination

et al. 2011

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“…residues of an organic insecticide applied during or after the growing stages to foodstuffs for human or animal consumption must be evaluated both lexicologically and analytically before the insecticide can be registered and licensed for general sale within the United States. In the absence of more specific and applicable analytical methods, some of the total chlorine methods (7,6,7) are considered to be capable of providing useful residue information when the insecticide contains organically bound chlorine. When insecticide-containing soil, plant, and animal extractives are involved, precise determinations of the ultimately released chloride ion are often difficult and questionable because of interfering accessory substances present (6).…”

Section: Persistingmentioning

confidence: 99%

“…The present method [briefly mentioned by Gunther and Blinn (6)] for the simple yet accurate determination of chloride ion was developed from that of Furman (4), Furman and Low (5), and Blaedel et al (2). It meets the exacting needs of routine microanalyses in conjunction with the combustion (7,6,7) of extractives from plant parts and soils treated with chlorinated insecticides. An additional advantage of this procedure is its applicability to measurement of chloride ion at concentrations of the order of, or considerably below, that arising from the silver chloride itself.…”

Section: Persistingmentioning

confidence: 99%

See 1 more Smart Citation

Residue Analysis, Direct Potentiometric Method for Chloride Ion Applied to Residues of Chlorinated Insecticides

Helmkamp¹,

Günther²,

Wolf³

et al. 1954

J. Agric. Food Chem.

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The quantitative determination of chlorinated-insecticide residues in treated foodstuffs by total chlorine methods is expedited and simplified by the exploitation of an unusually sensitive direct potentiometric method for chloride ion. This method uses a pH meter and a silver-silver chloride vs. calomel electrode system, and responds reproducibly to as little as 0.02 p.p.m. of chloride ion. With the equipment and procedures recommended, the useful range, without concentration or dilution stages, appears to be from 0.02 p.p.m. to 10,000 p.p.m.

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“…A discussion of the accuracy of organic microanalysis (94) indicates that the error is more often due to the method than to the analyst. General discussions have been published on the application of amperometric titrations (141), on errors in amperometric and starch-indicator methods (23), on ultramicromethods, apparatus, and techniques (2,47,143), and on recent developments in microanalysis (92,102) and microapparatus (76,175).…”

Section: General and Reviewsmentioning

confidence: 99%