Comparison of pyrolysis mass spectrometry with high performance liquid chromatography for the analysis of Cremophor EL in drugs and serum

Polyoxyethyleneglycerol triricinoleate 35 (Cremophor EL: CrEL) is a solubilization agent for hydrophobic drugs. Recently, CrEL has shown some side effects in patients. In the present work, we introduce pyrolysis–mass spectrometry (Py–MS) for the determination of CrEL in drugs and blood samples. Mass to charge (m/z) values of 89 and 138 of CrEL and 3-nitroaniline (as internal standard), respectively, were used for quantitative measurements by selected ion monitoring (SIM) method. At a probe pyrolysis temperature range of 350–450 °C the results are highly reproducible. Limit of detection (LOD), linearity and relative standard deviation (R.S.D., n=5) were determined to be 1 ng ml−1, 10 ng ml−1–100 mg ml−1 and 1.3%, respectively. The results of Py–MS are compared with those obtained by high performance liquid chromatography (HPLC) and show that time for analysis, sensitivity and linearity are far better.