Membraneless vaporization unit for direct analysis of solid sample

• Published in: Analytica chimica acta Vol. 597; no. 1; pp. 157 - 162
• Main Authors: Sereenonchai, K., Saetear, P., Amornthammarong, N., Uraisin, K., Wilairat, P., Motomizu, S., Nacapricha, D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30.07.2007; Elsevier
• Subjects: Analytical chemistry; Carbon dioxide; Carbonate; Chemistry; Direct analysis; Exact sciences and technology; Membraneless vaporization; Solid analysis; Spectrometric and optical methods; Membraneless vaporization; Carbonate; Solid analysis; Direct analysis; Carbon dioxide; Stirring; Hydrophobic compound; Flame spectrometry; Vaporization; Direct method; Absorption spectrometry; Calcium Carbonates; Detection limit; Membrane; Carbonates; Pervaporation; Atomic absorption spectrometry
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2007.06.036

A new apparatus, called ‘membraneless vaporization’ (MBL-VP) unit was designed and developed for direct analysis of solid samples. Solid analyte was converted into a gaseous form which then reacts with an indicator reagent. Change in absorbance was used to quantitate the analyte. Stirring with a magnetic bar was employed to facilitate the evaporation of the gas. Unlike the pervaporation technique, hydrophobic membrane was not required for this MBL-VP technique. Application of the membraneless technique for direct determination of calcium carbonate in calcium supplements, has shown to be very precise (R.S.D. = 2.5% for 0.16 mmol CO 3 2−), with detection limit of 0.5 mg CaCO 3. Results by this method agreed well with flame atomic absorption spectrometric method. Sample throughput was 20 samples h −1.