The influence of various conditions on laws of retention of lower alcohols and ketones from the gas phase by cobalt chloride(II)
Abstract
Sorbents consisted of transition metal salts have been proposed for isolation low molecular weight polar organic compounds more than 40 years ago. However, the possibilities of such sorbents investigated far from complete. We have found recently that cobalt chloride (II) has the highest adsorption affinity to lowmolecular oxygen-containing organic compounds (methanol, ethanol and acetone) from several tens of transition metal salts. On this indicator sorbents consisted of cobalt chloride surpass much hydrophobic adsorbents with high surface area, including activated carbon.
The purpose of this work - to research the influence of various conditions (the concentration of analytes, amount of cobalt chloride deposited on the support, the analyzed air flow rate through the sorption column) on retention of lower alcohols and ketones from the air flow by composite sorbents consisted of cobalt chloride for gas chromatographic determination of these analytes after thermal desorption. Cobalt chloride
(II) has a crystalline structure; therefore the aqueous solution of salt was applied to a macroporous support for gas chromatography - porohrom-3 to increase the surface area.
The effect of various conditions (the concentration of analytes, amount of cobalt chloride deposited on the support, the flow rate of air analyzed through the sorption column) on retention of lower alcohols and ketones from the air flow by composite sorbents consisted of cobalt chloride. It was found that the decrease in the concentration of analytes leads to a significant increase in their retention volumes. It creates favorable conditions for their sorption pre-concentration in the air analysis for the purpose of gas chromatographic determination at the level of maximum permissible concentration in the air of populated areas. The optimal amount of sorption-active salt in the composite sorbent is 20-30% by weight of the support. The retention parameters of analytes on developed sorbents altered slightly with an increase of the gas phase flow rate. It allows to use high flow rate of air analyzed in order to reduce the duration of sorption pre-concentration step.
Downloads
References
Isidorov V.A., Organicheskaya khimiya atmosfery, St-Petersburg, Khimiya, 1992, 288 p.
2.
Drugov Yu.S., Rodin A.A., Gazokhromatograficheskii analiz zagryaznennogo vozdukha, M., BINOM, 4-e izd., pererab. i dopoln. Laboratoriya znanii, 2006, 528 p.
3.
Demeestere K., Dewulf J., Witte B., Langenhove H., J. Chromatogr. A, 2007, Vol. 1153, pp. 130-144.
4.
Woolfenden E., J. Chromatogr. A, 2010, Vol. 1217, pp. 2674-2684.
5.
Ras M.R., Borrull F., Marce R.M., Trends Anal. Chem., 2009, Vol. 28, pp. 347-361.
6. Belyakova L.D., Kalpakian A.M., Kiselev A.V., Chromatographia, 1974, Vol. 7, pp. 1418.
7.
Rodinkov O.V. et al., J. of Analytical Chemistry, 2014, Vol. 69, No 4, pp. 390-394.
8.
Rodinkov O.V. et al., Talanta, 2015, Vol. 144, pp. 427-431.
9.
Rodinkov O.V., Zhuravlyova G.A., Vaskova E.A., Platonov I.A., Anal. Methods, 2015, Vol. 7, pp. 458-465.
10.Rodinkov O.V., Zhuravleva G.A., Bugaichenko A.S., Moskvin L.N., Patent RF, no. 2564344, 2015.
11. Lur'e A., Hromatograficheskie materialy (spravochnik). M., Khimiya Publ., 1978, 440 p.
12.Vitenberg A.G, Ioffe B.V., Gazovaya ekstraktsiya v khromatograficheskom analize: Parofaznyi analiz i rodstvennye metody. L., Khimiya Publ., 1982, 280 p.
13. Nemirovskii A.M., Ind. Lab, 1996, Vol. 62, No 3, pp. 13-16.
