Determination of chromium(III), chromium(VI) and total chromium in chromate and trivalent chromium conversion coatings by electrospray ionization mass spectrometry

• Published in: Talanta (Oxford) Vol. 88; pp. 533 - 536
• Main Authors: Hotta, Hiroki, Yata, Katsuya, Kamarudin, Kamurul Fakir Bin, Kurihara, Shota, Tsunoda, Kin-ichi, Fukumoto, Natsuo, Kojima, Isao, Kinugasa, Shin-ichi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.01.2012; Elsevier
• Subjects: Analytical chemistry; Chemistry; Chromate and trivalent chromium conversion coatings; Chromium; Chromium(III); Chromium(VI); Conversion coating; Electrospray ionization mass spectrometry; Emission analysis; Exact sciences and technology; Inductively coupled plasma; Ionization; Mass spectrometry; Spectrometric and optical methods; Spectroscopy; Total chromium; Trivalent chromium; Total chromium; Chromium(III); Chromium(VI); Electrospray ionization mass spectrometry; Chromate and trivalent chromium conversion coatings; Ascorbic acid; Atomic emission spectrometry; Method; Coatings; Inductive coupling plasma spectrometry; Chromates; Conversion; Electrospray; Chemical ionization; Reduction; Chromium III; Detection limit; Spectrophotometry; Mass spectrometry; Chromium VI
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2011.11.028

► Electrospray ionization mass spectrometry was for the first time applied to determine trace amounts of chromium(III), chromium(VI) and total Chromium. ► The method is highly sensitive and selective. ► It was successfully applied to analyze chromate and trivalent chromium conversion coatings. Developed were the determination methods of CrVI and CrIII by electrospray ionization mass spectrometry, where HCrO4− (m/z 117) and [CrIII(cydta)]− (m/z 394) were measured, respectively. Moreover, total Cr was also determined by measuring [CrIII(cydta)]− after reduction of CrVI with ascorbic acid. Here, cydta denotes trans-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid. The detection limits were ca. 13nmol/dm3 for CrVI and 56nmol/dm3 for CrIII and total Cr. The proposed methods were applied to analyze chromate and trivalent chromium conversion coatings and gave consistent results with those obtained by a diphenylcarbazide spectrophotometric method for CrVI and ICP-AES for total Cr.