A single-drop microextraction (SDME) method followed by in-syringe derivatization and GC-MS determination has been developed for analysis of five parabens, including methyl, ethyl, isopropyl, n-propyl and n-butyl paraben in water samples and cosmetic products. N,O-Bis(trimethylsilyl)acetamide (BSA) was used as derivatization reagent. Derivatization reaction was performed inside the syringe barrel using 0.4 microL of BSA. Parameters that affect the derivatization yield such as temperature and time of the reaction were studied. In addition, experimental SDME parameters such as selection of organic solvent, addition of salt, extraction time and extraction temperature were investigated and optimized. The RSD of the method for aqueous samples varied from 8.1 to 13%. The LODs ranged from 0.001 (n-butyl paraben) to 0.015 (methyl paraben) microg/L, and the enrichment factors were between 23 and 150.

Analysis of testosterone was accomplished using corona discharge ion mobility spectrometry. Molecular imprinted polymer was used for the extraction and pre-concentration of testosterone. Analytical parameters including precision, dynamic range and detection limit were obtained. The linear dynamic range was from 10 to 250 ng/mL and the limit of detection was 0.9 ng/mL. The proposed method was used for analysis of testosterone in urine samples. A urine sample from a 3-year-old girl was used as the blank. The RSD was below 10%. The obtained results from the method were also compared with the standard method for analysis of testosterone using SPE-HPLC analysis. The results demonstrate the accuracy of the method.

No abstract

No abstract

No abstract