Determination of low levels of poly(ethylene glycol) 400 in plasma and urine by capillary gas chromatography-selected ion-monitoring mass spectrometry after solid-phase extraction

Determination of polyethylene glycols of different molecular weight in the stratum corneum

“…1), except for oligomer with MW of 590 Da, for which the loss was somewhat higher (up to 15% within 14 h). The stability of the derivatives was better than that reported in the study of Fakt and Ervik [9]. They also used PFPA for acylation of polydisperse PEG400 reporting gradual deterioration of derivatives after only 1 h. After 24 h, the percentage of initial concentration in that study was about 60%.…”

“…This is in contrast with the previous studies, where the identification of the oligomers in the polydisperse mixtures was performed only indirectly [2][3][4][5]9,11,14,15]. In most of these studies, the identification of the PEG oligomers in the chromatogram was done by the comparison of the retention time with that of a smaller individual oligomer (di-, tri-or tetraethylene glycol) which was available as a pure chemical [11,14,15].…”

“…For the determination of PEGs in biological material, several high-performance liquid chromatographic (HPLC) and gas chromatographic (GC) methods have been described [4,[9][10][11][12][13][14][15][16]. The majority of the HPLC methods are based on refractive index detection.…”

“…However, the HPLC methods were primarily developed for the analysis of PEGs in urine or blood and could not be applied in the present study due to their low sensitivity. Higher sensitivity was reported in the GC methods which were based on derivatization of hydroxy groups followed by gas chromatography-electron capture detection (GC-ECD) [9]. Derivatization with different reagents such as acetic acid anhydride, trifluoroacetic acid (TFAA), pentafluoropropionic anhydride (PFPA) and heptafluorobutyric anhydride (HFBA) was investigated.…”

“…Derivatization with different reagents such as acetic acid anhydride, trifluoroacetic acid (TFAA), pentafluoropropionic anhydride (PFPA) and heptafluorobutyric anhydride (HFBA) was investigated. However, the major problem in these procedures was a poor stability of the derivatives [4,5,9,16].…”