Hollow fibre liquid phase microextraction in combination with an in situ derivatization followed by gas chromatographic determination is suggested for parabens sampling and preconcentration. The derivatization was carried out with acetic anhydride in alkaline conditions maintained with di-potassium hydrogen phosphate. The effects of the extraction solvent type, extraction time and the ionic strength of the solution on the extraction efficiency were investigated. Chlorobenzene containing n-hexadecane as the internal standard was used as an extracting solvent. The calibration graphs were linear up to 10 mg L^–1, correlation coefficients were 0.997–0.999, and detection limits were 18, 9.1, 6.4 and 5.1 μg L^–1 for methylparaben, ethylparaben, propylparaben and butylparaben, respectively. Repeatabilities of the results were acceptable with relative standard deviations up to 9.2%. The possibility to apply the proposed method for paraben determination in facial tonics was demonstrated.

Issues:

2017 - Vol.28
No. 1, No. 2, No. 3, No. 4

2016 - Vol.27
No. 1, No. 2, No. 3, No. 4

2015 - Vol.26
No. 1, No. 2, No. 3, No. 4

2014 - Vol.25
No. 1, No. 2, No. 3, No. 4

2013 - Vol.24
No. 1, No. 2, No. 3, No. 4

2012 - Vol.23
No. 1, No. 2, No. 3, No. 4

2011 - Vol.22
No. 1, No. 2, No. 3, No. 4

2010 - Vol.21
No. 1, No. 2-4

2009 - Vol.20
No. 1, No. 2, No. 3, No. 4

2008 - Vol.19
No. 1, No. 2, No. 3-4

2007 - Vol.18
No. 1, No. 2, No. 3, No. 4

2006 - Vol.17
No. 1, No. 2-3, No. 4

2005 - Vol.16
No. 1, No. 2, No. 3-4

2004 - Vol.15
No. 1, No. 2, No. 3, No. 4

2003 - Vol.14
No. 1, No. 2, No. 3, No. 4

2002 - Vol.13
No. 1, No. 2, No. 3, No. 4

2001 - Vol.12
No. 1, No. 2, No. 3, No. 4