Solubility and thermodynamic function of vanillin in ten different environmentally benign solvents.

Solubility and thermodynamic function of vanillin in ten different environmentally benign solvents.

Food chemistry (2015-03-15)

Faiyaz Shakeel, Nazrul Haq, Nasir A Siddiqui

ABSTRACT

The solubility of vanillin in ten different environmentally benign solvents namely water, ethanol, ethylene glycol (EG), ethyl acetate (EA), isopropanol (IPA), propylene glycol (PG), polyethylene glycol-400 (PEG-400), Transcutol, butanol-1 and butanol-2 was measured and correlated at T=(298-318)K. The resulting experimental data were correlated with the modified Apelblat and Van't Hoff models. Both the models showed good correlation of experimental solubility data with calculated ones with root mean square deviations in the range of (0.08-1.55)%. The mole fraction solubility of vanillin was observed highest in PEG-400 (4.29 × 10(-1) at 298 K) followed by Transcutol, EA, butanol-2, ethanol, EG, PG, IPA, butanol-1 and water from T=(298-318)K. The results of thermodynamic function in terms of dissolution enthalpy, Gibbs energy and dissolution entropy showed endothermic, spontaneous and entropy-driven dissolution of vanillin in all environmentally benign solvents.

MATERIALS

Product Number

Brand

Product Description

733466

Sigma-Aldrich

Acetonitrile, electronic grade, 99.999% trace metals basis

02891

Sigma-Aldrich

Ethanol, purum, secunda spirit, denaturated with 2% 2-butanone, S15, ~96% (based on denaturant-free substance)

82281

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1,2-Propanediol, tested according to Ph. Eur.

16033

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1,2-Propanediol, meets analytical specification of Ph. Eur., BP, USP, ≥99.5%

110086

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Acetonitrile, ReagentPlus^®, 99%

34442

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493546

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Ethyl alcohol, Pure, 200 proof, meets USP testing specifications

459844

Sigma-Aldrich

Ethyl alcohol, Pure, 200 proof, ACS reagent, ≥99.5%

L010300

Sigma-Aldrich

Ultrapure Acetonitrile

1601340

USP

Residual Solvent Class 2 - Acetonitrile, United States Pharmacopeia (USP) Reference Standard

51976

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Ethanol, BioUltra, for molecular biology, ≥99.8%, (absolute alcohol, without additive, A15 o¹)

02851

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Ethanol, for residue analysis

02890

Sigma-Aldrich

Ethanol, purum, fine spirit, denaturated with 2% 2-butanone, F25 MEK¹, ~96% (based on denaturant-free substance)

34851

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02882

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Ethanol, purum, absolute ethanol, denaturated with 2% 2-butanone, A15 MEK¹, ≥99.8% (based on denaturant-free substance)

271004

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34998

Sigma-Aldrich

Acetonitrile, HPLC Plus, ≥99.9%

439134

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Acetonitrile, suitable for HPLC, gradient grade, ≥99.9%

45983

Supelco

Acetonitrile, analytical standard

360457

Sigma-Aldrich

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494445

Sigma-Aldrich

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W217816

Sigma-Aldrich

Butyl alcohol, natural, ≥99.5%, FCC, FG

12279

Supelco

1,2-Propanediol, analytical standard

P50404

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1,3-Propanediol, 98%

398039

Sigma-Aldrich

1,2-Propanediol, ACS reagent, ≥99.5%

134368

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1,2-Propanediol, ReagentPlus^®, 99%

82280

Sigma-Aldrich

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02483

Supelco

Ethanol, standard for GC

02857

Sigma-Aldrich

Ethanol, purum, fine spirit, denaturated with 4.8% methanol, F25 METHYL¹, ~96% (based on denaturant-free substance)

29221

Sigma-Aldrich

Ethanol, tested according to Ph. Eur.