{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,19]],"date-time":"2026-10-19T21:06:32Z","timestamp":1792443992282,"version":"4.5.0"},"reference-count":50,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2022,2,11]],"date-time":"2022-02-11T00:00:00Z","timestamp":1644537600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>A new liquid\u2014liquid extraction system for molybdenum(VI) was studied. It contains 4-nitrocatechol (4NC) as a complexing chromogenic reagent and benzalkonium chloride (BZC) as a source of heavy cations (BZ+), which are prone to form chloroform-extractable ion-association complexes. The optimum conditions for the determination of trace molybdenum(VI) were found: concentrations of 4NC and BZC (7.5 \u00d7 10\u22124 mol dm\u22123 and 1.9 \u00d7 10\u22124 mol dm\u22123, respectively), acidity (3.75 \u00d7 10\u22122 mol dm\u22123 H2SO4), extraction time (3 min), and wavelength (439 nm). The molar absorptivity, limit of detection, and linear working range were 5.5 \u00d7 104 dm3 mol\u22121 cm\u22121, 5.6 ng cm\u22123, and 18.6\u20133100 \u03bcg cm\u22123, respectively. The effect of foreign ions was examined, and the developed procedure was applied to the analysis of synthetic mixtures and real samples (potable waters and steels). The composition of the extracted complex was 1:1:2 (Mo:4NC:BZ). Three possible structures of its anionic part [MoVI(4NC)O2(OH)2]2\u2212 were discussed based on optimizations at the B3LYP\/3-21G level of theory, and simulated UV\/Vis absorption spectra were obtained with the TD Hamiltonian.<\/jats:p>","DOI":"10.3390\/molecules27041217","type":"journal-article","created":{"date-parts":[[2022,2,13]],"date-time":"2022-02-13T20:34:45Z","timestamp":1644784485000},"page":"1217","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Spectrophotometric Determination of Molybdenum(VI) as a Ternary Complex with 4-Nitrocatechol and Benzalkonium Chloride"],"prefix":"10.3390","volume":"27","author":[{"given":"Vidka V.","family":"Divarova","sequence":"first","affiliation":[{"name":"Department of Chemical Sciences, Faculty of Pharmacy, Medical University of Plovdiv, 120 Buxton Bros Str., 4004 Plovdiv, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antoaneta","family":"Saravanska","sequence":"additional","affiliation":[{"name":"Department of Chemical Sciences, Faculty of Pharmacy, Medical University of Plovdiv, 120 Buxton Bros Str., 4004 Plovdiv, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Galya","family":"Toncheva","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry, University of Plovdiv \u2018Paisii Hilendarskii\u2019, 24 Tsar Assen St., 4004 Plovdiv, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6508-4132","authenticated-orcid":false,"given":"Nikolina","family":"Milcheva","sequence":"additional","affiliation":[{"name":"Department of Chemical Sciences, Faculty of Pharmacy, Medical University of Plovdiv, 120 Buxton Bros Str., 4004 Plovdiv, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vassil B.","family":"Delchev","sequence":"additional","affiliation":[{"name":"Faculty of Chemistry, University of Plovdiv \u2018Paisii Hilendarskii\u2019, 24 Tsar Assen St., 4004 Plovdiv, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1360-8977","authenticated-orcid":false,"given":"Kiril","family":"Gavazov","sequence":"additional","affiliation":[{"name":"Department of Chemical Sciences, Faculty of Pharmacy, Medical University of Plovdiv, 120 Buxton Bros Str., 4004 Plovdiv, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1007\/s40436-019-00270-5","article-title":"Editorial: Industrial relevance of molybdenum in China","volume":"8","author":"Outteridge","year":"2020","journal-title":"Adv. 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