ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUtilization of the amount of information in evaluation of analytical methodsC. Liteanu and I. RicaCite this: Anal. Chem. 1979, 51, 12, 1986–1995Publication Date (Print):October 1, 1979Publication History Published online1 May 2002Published inissue 1 October 1979https://pubs.acs.org/doi/10.1021/ac50048a022https://doi.org/10.1021/ac50048a022research-articleACS PublicationsRequest reuse permissionsArticle Views42Altmetric-Citations14LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Membranes consisting of a methyl polymethacrylate or collodion support containing sparingly soluble inorganic or organic acids can be used for end-point detection in acid—base titrations in high-conductivity media. The collodion + Na3[As(Mo3O10)4].nH2O + Na-Alassion CS membrane is a very good conductometric sensor if given preliminary treatment to form molybdic acid. The conductivity jump with this membrane starts at pH ∼ 7 and permits titration of strong acid down to 10−4M concentration in highly conducting medium. Similar membranes containing some organic acids such as benzoic, o-chlorobenzoic, and o-phthalic also behave as conductometric sensors, giving a conductivity change at a ph which depends on the dissociation constant of the organic acid used and on the way it interacts with the support and the conducting medium used.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStatistical approach for the selectivity of ion-selective membrane electrodesCandin. Liteanu, Elena. Hopirtean, Ionel C. Popescu, Ion. Rica, and Eugenia. StefanigaCite this: Anal. Chem. 1978, 50, 8, 1202–1209Publication Date (Print):July 1, 1978Publication History Published online1 May 2002Published inissue 1 July 1978https://pubs.acs.org/doi/10.1021/ac50030a049https://doi.org/10.1021/ac50030a049research-articleACS PublicationsRequest reuse permissionsArticle Views37Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

As the point of intersection in linear-branch titration curves results from two optimized linear regressions, calculated by least-squares from n1 and n2 pairs of values of the signal y as a function of the added volume of titrant υ, the value of the equivalence volume Ve has the character of an estimated average Ve hence a confidence interval is associated with it. If the point of intersection Ve belongs concomitantly to both regressions then the same value of ye should correspond to the two extreme values V′e and V′e of the confidence interval as to Ve itself. Consequently, the two segments of the confidence interval are obtained by averaging each of the two unequal segments of the separate confidence intervals. Alternatively, considering that multiple estimates of Ve can be obtained, the confidence interval can be calculated from the normally distributed random variables Δa′ and Δb′ of the two linear regressions.

To estimate the time stability of a nitrate-selective liquid membrane electrode, the serial correlation method was used. From the values of the random variableR1 (the coefficient for serial correlation) results that the statistical conclusion, namelyy=f(n), could not be identical with that one concerning the parameters of the transfer functiony=f(c).

FeCl 4 − -selective liquid membrane-electrodes were prepared by using triphenylpyrilium, phenylbenzopyrilium and cetylpyridinium tetrachloroferrates and dichloroethane or tetrachloroethane as solvents. With regard to selectivity, sensitivity and concentration range the triphenylpyrilium electrode in dichloroethane proved to be most advantageous. Its response is practically Nernstian in the concentration range of 10−1 to 10−4 M FeCl 4 − , ZnCl2, CuCl2, MnCl2, NiCl2, CdCl2, AlCl3, NO 3 − and Br− do not cause any interference.

An electrode based on an organic free radical and sensitive to redox systems is described.