HPLC Determination of pKa of Parabens and Investigation on their Lipophilicity Parameters

Angelov, T.; Vlasenko, Hanna S.; Tashkov, W.

doi:10.1080/10826070701738787

Cited by 87 publications

(35 citation statements)

References 14 publications

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“…For example, clotrimazole, ketoconazole, miconazole, fluconazole, and carbendazim have been detected in Belgian WWTP effluents at concentrations up to 27,90,36,140, and 980 ngL −1 , respectively [6], and climbazole and thiabendazole have been found in German WWTP effluents at average concentrations of 443 and 8.2 ngL −1 [7]. The insect repellent DEET has frequently been detected in WWTP effluents at concentrations ranging between 51 and 773.9 ngL −1 [8][9][10][11], and methylparaben, ethylparaben, propylparaben, and butylparaben in Spanish rivers and 4,5-dichloro-2-n-octylisothiazolinone (DCOIT) in Spanish coastal regions have been detected at maximum concentrations of 54, 30, 105, 7, and 3700 ng L −1 , respectively [12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Determination of biocides in different environmental matrices by use of ultra-high-performance liquid chromatography–tandem mass spectrometry

et al. 2012

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A sensitive and robust method using solid-phase extraction and ultrasonic extraction for preconcentration followed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS-MS) has been developed for determination of 19 biocides: eight azole fungicides (climbazole, clotrimazole, ketoconazole, miconazole, fluconazole, itraconazole, thiabendazole, and carbendazim), two insect repellents (N,N-diethyl-3-methylbenzamide (DEET), and icaridin (also known as picaridin)), three isothiazolinone antifouling agents (1,2-benzisothiazolinone (BIT), 2-n-octyl-4-isothiazolinone (OIT), and 4,5-dichloro-2-n-octyl-isothiazolinone (DCOIT)), four paraben preservatives (methylparaben, ethylparaben, propylparaben, and butylparaben), and two disinfectants (triclosan and triclocarban) in surface water, wastewater, sediment, sludge, and soil. Recovery of the target compounds from surface water, influent, effluent, sediment, sludge, and soil was mostly in the range 70-120 %, with corresponding method quantification limits ranging from 0.01 to 0.31 ngL −1 , 0.07 to 7.48 ngL −1 , 0.01 to 3.90 ngL −1 , 0.01 to 0.45 ngg −1 , 0.01 to 6.37 ngg −1 , and 0.01 to 0.73 ngg −1 , respectively. Carbendazim, climbazole, clotrimazole, methylparaben, miconazole, triclocarban, and triclosan were detected at low ngL −1 (or ngg −1 ) levels in surface water, sediment, and sludge-amended soil. Fifteen target compounds were found in influent samples, at concentrations ranging between 0.4 (thiabendazole) and 372 ng L −1 (methylparaben). Fifteen target compounds were found in effluent samples, at concentrations ranging between 0.4 (thiabendazole) and 114 ngL −1 (carbendazim). Ten target compounds were found in dewatered sludge samples, at concentrations ranging between 1.1 (DEET) and 887 ngg −1 (triclocarban).

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Section: Introductionmentioning

confidence: 99%

Determination of biocides in different environmental matrices by use of ultra-high-performance liquid chromatography–tandem mass spectrometry

et al. 2012

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“…Values greater than 8.0 were not feasible because benzoic acid esters underwent hydrolysis. 31 Two processes occur simultaneously in the parabens molecules. The first process refers to the protonation of oxygen atom in the ester group (C=O), whereas the second process concerns deprotonation of the hydroxyl group.…”

Section: Resultsmentioning

confidence: 99%

“…The first process refers to the protonation of oxygen atom in the ester group (C=O), whereas the second process concerns deprotonation of the hydroxyl group. 31 Protonation is relatively slow and strongly depends on the size of the ester aliphatic chain. Longer aliphatic chains increase the strength of the positive inductive effect, thereby raising the electron density on oxygen (C=O).…”

Section: Resultsmentioning

confidence: 99%

Determination of Parabens in Breast Milk Samples by Dispersive Liquid-Liquid Microextraction (DLLME) and Ultra-High-Performance Liquid Chromatography Tandem Mass Spectrometry

Grecco¹,

Souza²,

Acquaro³

et al. 2018

J. Braz. Chem. Soc.

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A reliable method was developed and validated based on dispersive liquid-liquid microextraction (DLLME) and ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) to determine simultaneously methylparaben (MePB), ethylparaben (EtPB), propylparaben (PrPB), and butylparaben (BuPB) in breast milk samples. A central composite design 2 4 with four independent variables and five levels of variance was used to optimize the DLLME conditions. The DLLME/UHPLC-MS/MS method was linear from 5 (lower limit of quantification, LLOQ) to 100 ng mL -1 (upper limit of quantification, ULOQ). The inter-assay and intra-assay precision values presented coefficients of variation (CVs) lower than 15%, and the relative standard error of the inter-and intra-assay accuracy values was lower than 10.4%. The DLLME/UHPLC-MS/MS method was successfully applied to determine parabens in human milk samples obtained from sixteen volunteer lactating mothers.

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“…As the lipophilicity parameter (logP O/W ) for these compounds increases with an increase in the size of their ester group (1.91, 2.34, 2.94, and 3.50, respectively, for MP, EP, PP, and BP [17]), and the solubility in aqueous solutions decreases, the electrochemical properties of parabens should be examined in organic solvents. The investigations on the selection of the solvent started from applying AN which is used most frequently for anodic processes [33].…”

Section: Choice Of the Solution Compositionmentioning

confidence: 99%

“…The antimicrobial activity of parabens increases with an increase in the size of the ester group [16,17], which results from the fact that the lipophilicity of these compounds increases in the same direction [17,18]. This property makes it easier for parabens to get thorough the cellular membrane [17]. Since microbial replication generally occurs in the water phase of oil/water systems, the amount of parabens dissolved in water determines their preservative efficiency.…”

Section: Introductionmentioning

confidence: 99%

Anodic oxidation of parabens in acetic acid–acetonitrile solutions

Michałkiewicz

2012

J Appl Electrochem

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The electrochemical properties of esters of p-hydroxybenzoic acid, called parabens, were investigated on a carbon fiber microelectrode and on a glassy carbon macroelectrode in glacial acetic acid containing 20 % acetonitrile (v/v) and sodium acetate as a supporting electrolyte. The anodic oxidation of parabens in this medium proceeds in a single stage giving well-shaped peaks or waves in the same potential region of above 1.0 V (vs. Ag/AgCl). The electrode process was characterized as being quasireversible, diffusion-controlled, and proceeds with the exchange of one electron and one proton. Phenoxyl radicals as products of the electrode process are chemically unstable and participate in the successive irreversible homogenous reactions resulting in electroinactive products (E q C i mechanism). Smaller oxidation potentials for parabens in comparison to such unsaturated fatty acids as oleic, linoleic, and linolenic ones indicate that these compounds can show antioxidative properties. Since parabens are often used as preservatives in many products, the results presented can be found useful in the determination of their total content in real samples.

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HPLC Determination of pKa of Parabens and Investigation on their Lipophilicity Parameters

Cited by 87 publications

References 14 publications

Determination of biocides in different environmental matrices by use of ultra-high-performance liquid chromatography–tandem mass spectrometry

Determination of biocides in different environmental matrices by use of ultra-high-performance liquid chromatography–tandem mass spectrometry

Determination of Parabens in Breast Milk Samples by Dispersive Liquid-Liquid Microextraction (DLLME) and Ultra-High-Performance Liquid Chromatography Tandem Mass Spectrometry

Anodic oxidation of parabens in acetic acid–acetonitrile solutions

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