The Ultraviolet Spectrometric Determination of the Three Isomeric Toluenesulfonic Acids in Excess of Aqueous Sulfuric Acid.

Cerfontain, H.; Duin, H. G. J.; Vollbracht, L.

doi:10.1021/ac60201a026

Cited by 29 publications

(8 citation statements)

References 10 publications

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“…Many methods for the analysis of sulfonic acids are accomplished using ultraviolet spectrometry (5-9). To obtain high precision in the analysis of multicomponent systems, the absorbances of the mixture and the pure components must be determined at a large number of wavelengths (1,8). For an evaluation of the unknown concentrations, a least squares treatment is applied.…”

Section: Contributionmentioning

confidence: 99%

Gas-solid chromatography with salt-modified porous silica beads

Isbell¹,

Sawyer²

1969

Anal. Chem.

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The differential enthalpies, entropies, and free energies of adsorption for the functional groups of substituted hydrocarbons on salt-modified porous silica beads have been determined using elution gas chromatography. The effect of adsorbent surface area and of surface modification on these thermodynamic parameters has been studied to establish optimum conditions for selective separations. Various coating salts are compared and data are presented for the functional group contributions to adsorption on Porasil C modified with Na2S04, NaCI, LiBr, Na3P04, Na2Mo04, NiS04, C0SO4, AI2(S04)3, and Cr2(S04)3. Surface treatment of the porous silica with hexamethyldisilazane eliminates the specific interactions due to olefinic and aromatic pi electron systems. This provides a basis for evaluation of substituent contributions to aromatic pi electron density. Examples of optimized separations of difficult mixtures are presented.Use of salt-modified activated aluminas in gas-solid chromatography, which was discussed initially by Scott (/), has been the subject of several detailed studies (2, 3). Recent investigations (4-7) have established that the interaction between a sórbate molecule and a salt-modified alumina is a combination of nonspecific and specific contributions. This previous work has shown that the overall adsorbentadsorbate interaction is dependent upon the nature of the modifying salt and the adsorbent. As a part of this earlier work, salt-modified porous silica beads have been compared with modified aluminas. The porous silica beads have desirable properties for gas-solid chromatography and provide selective interactions that are different from those for aluminas.

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Section: Contributionmentioning

confidence: 99%

Gas-solid chromatography with salt-modified porous silica beads

Isbell¹,

Sawyer²

1969

Anal. Chem.

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“…Reference 6 contains a study where p > r was used solely for the detection of potential interferences. Several workers have shown that by using p > r for spectrophotometry, the highest precision for multicomponent analysis is obtainable (8)(9)(10)(11)(12)(13). With p > r, the system of linear absorption equations is overdetermined which permits the most probable composition to be estimated as compared to the exact solution of the linear equations for p = r. Another advantage of p > r is that improved signal-tonoise ratios are obtainable which result from the overdetermined system using all spectral information available throughout the absorption bands.…”

Section: Correspondence Precision and Stability For The Generalized S...mentioning

confidence: 99%

Precision and stability in the generalized standard addition method

Kalivas¹

1983

Anal. Chem.

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“…The quantitative analysis of mixtures of arenesulfonic acid isomers in aqueous or sulfuric acid solution can conveniently be performed by the ultraviolet spectrophoto-metric multicomponent analysis (1,2). This method of analysis is based on a comparison of the UV absorption spectrum of the mixture with the spectra of the constituting sulfonic acids.…”

Section: Quantitative Nuclear Magnetic Resonance Analysis Of Mixtures...mentioning

confidence: 99%

Quantitave nuclear magnetic resonance analysis of mixtures of isomeric arenesulfonic acids in sulfonation mixtures

Cerfontain¹,

Koeberg-Telder²,

Kruk³

et al. 1974

Anal. Chem.

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contrast, the silicon-to-gallium count ratio did respond to change in aspiration rate of gallium solution but showed an insensitivity similar to the silicon-to-aluminum ratio above a critical aspiration rate of approximately 1 ml/ min. The relative standard deviation was 6.0% for flows of 1.0 to 2.48 ml/min. Matrix Effects. Matrix effects in spark analysis have been studied previously; however, matrix effects, especially interelement effects, are generally treated empirically. The recent use of atmospheres other than air (14-16) tends to reduce surface oxidation, which has been shown to account for some matrix effects ( 17), but the liquid layer technique offers another approach.For determination of silicon in aluminum alloys, a single analytical curve obtained by using the liquid layer technique replaced a number of analytical curves required without the liquid layer. The curves in Figure 10 are ex-(16) C. K.

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The Ultraviolet Spectrometric Determination of the Three Isomeric Toluenesulfonic Acids in Excess of Aqueous Sulfuric Acid.

Cited by 29 publications

References 10 publications

Gas-solid chromatography with salt-modified porous silica beads

Gas-solid chromatography with salt-modified porous silica beads

Precision and stability in the generalized standard addition method

Quantitave nuclear magnetic resonance analysis of mixtures of isomeric arenesulfonic acids in sulfonation mixtures

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