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Potentiometric Responses of Ion-Selective Electrodes Doped with Diureidocalix[4]arene towards Un-dissociated Benzoic Acid

View Article: PubMed Central

ABSTRACT

Diureidocalix[4]arene have been applied as new ionophore in liquid membrane electrode (ISE) sensitive towards un-dissociated benzoic acid. The electrode demonstrated response towards benzoic acid with the detection limit 2.0 × 10-4 M which is sufficient for the determination of benzoic acid added to beverages as preservative in milimolar concentration. The selectivity coefficients measured by the matched potential method (MPM) showed its good selectivity against common anions present in drink samples. All measurements were made in presence of 1.0 × 10-2 M NaHSO4 pH 3.0 in order to reduce the influence of OH-. The applicability of diureidocalix[4]arene incorporated ISE has been checked by recovery test of benzoic acid in the presence of artificial drink matrix and by standard addition method.

No MeSH data available.


Response time towards benzoic acid addition. Aliquot of the stock solution 1.0 × 10-2 M analyte was added to 100.0 ml 0.01 M Na2SO4, pH 3.0 to increase acid concentration from 1.0 × 10-4 M to 0.5 × 10-2 M.
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f4-sensors-07-01655: Response time towards benzoic acid addition. Aliquot of the stock solution 1.0 × 10-2 M analyte was added to 100.0 ml 0.01 M Na2SO4, pH 3.0 to increase acid concentration from 1.0 × 10-4 M to 0.5 × 10-2 M.

Mentions: A response time is important parameter which characterize ISEs. Figure 4 illustrates a representative plot of the potential changes vs time for electrode with diureidocalix[4]arene and lipophilic salt TDDMACl after additions aliquots of 1.0 × 10-2 M aqueous stock solution of benzoic acid. The electrode responses towards changes in concentration of benzoic acid were relatively fast (ca. 100 s) within the whole concentration range, when we assume response mechanism including more than one step, which are necessary in the case of uncharged analytes.


Potentiometric Responses of Ion-Selective Electrodes Doped with Diureidocalix[4]arene towards Un-dissociated Benzoic Acid
Response time towards benzoic acid addition. Aliquot of the stock solution 1.0 × 10-2 M analyte was added to 100.0 ml 0.01 M Na2SO4, pH 3.0 to increase acid concentration from 1.0 × 10-4 M to 0.5 × 10-2 M.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3814874&req=5

f4-sensors-07-01655: Response time towards benzoic acid addition. Aliquot of the stock solution 1.0 × 10-2 M analyte was added to 100.0 ml 0.01 M Na2SO4, pH 3.0 to increase acid concentration from 1.0 × 10-4 M to 0.5 × 10-2 M.
Mentions: A response time is important parameter which characterize ISEs. Figure 4 illustrates a representative plot of the potential changes vs time for electrode with diureidocalix[4]arene and lipophilic salt TDDMACl after additions aliquots of 1.0 × 10-2 M aqueous stock solution of benzoic acid. The electrode responses towards changes in concentration of benzoic acid were relatively fast (ca. 100 s) within the whole concentration range, when we assume response mechanism including more than one step, which are necessary in the case of uncharged analytes.

View Article: PubMed Central

ABSTRACT

Diureidocalix[4]arene have been applied as new ionophore in liquid membrane electrode (ISE) sensitive towards un-dissociated benzoic acid. The electrode demonstrated response towards benzoic acid with the detection limit 2.0 × 10-4 M which is sufficient for the determination of benzoic acid added to beverages as preservative in milimolar concentration. The selectivity coefficients measured by the matched potential method (MPM) showed its good selectivity against common anions present in drink samples. All measurements were made in presence of 1.0 × 10-2 M NaHSO4 pH 3.0 in order to reduce the influence of OH-. The applicability of diureidocalix[4]arene incorporated ISE has been checked by recovery test of benzoic acid in the presence of artificial drink matrix and by standard addition method.

No MeSH data available.