JOURNAL OF MASS SPECTROMETRY J. Mass Spectrom. 2003; 38: 917–923 Published online 21 August 2003 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jms.529 SPECIAL FEATURE: PERSPECTIVE Determination of estrogens and progestogens by mass spectrometric techniques (GC/MS, LC/MS and LC/MS/MS) M. Silvia D ´ ıaz-Cruz, 1 Mar ´ ıa J. L ´ opez de Alda, 2 Ram ´ on L ´ opez 2 and Dami ` a Barcel ´ o 2∗ 1 Department of Analytical Chemistry, Faculty of Chemistry, University of Barcelona, Diagonal 647, 08028 Barcelona, Spain 2 Department of Environmental Chemistry, IIQAB-CSIC, c/Jordi Girona 18- 26, 08034 Barcelona, Spain Received 16 June 2003; Accepted 3 August 2003 Steroid sex hormones and related synthetic compounds have been shown to provoke alarming estrogenic effects in aquatic organisms, such as feminization, at very low concentrations (ng/L or pg/L). In this work, different chromatographic techniques, namely, gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS), are discussed for the analysis of estrogens, both free and conjugated, and progestogens, and the sensitivities achieved with the various techniques are inter-compared. GC/MS analyses are usually carried out after derivatization of the analytes with bis(trimethylsilyl)trifluoroacetamide (BSTFA). For LC/MS and LC/MS/MS analyses, different instruments, ionization techniques (electrospray (ESI) and atmospheric pressure chemical ionization (APCI)), ionization modes (negative ion (NI) and positive ion (PI)) and monitoring modes (selected ion monitoring (SIM) and selected reaction monitoring (SRM)) are generally employed. Based on sensitivity and selectivity, LC/ESI-MS/MS is generally the method of choice for determination of estrogens in the NI mode and of progestogens in the PI mode (instrumental detection limits (IDLs) 0.1 – 10 ng/mL). IDLs achieved by LC/ESI-MS in the SIM mode and by LC/ESI-MS/MS in the SRM mode were, in general, comparable, although the selectivity of the latter is significantly higher and essential to avoid false positive determinations in the analysis of real samples. Conclusions and future perspectives are outlined. Copyright  2003 John Wiley & Sons, Ltd. INTRODUCTION During the last decades, a large number of chemicals with proved acute toxicity, mutagenicity or carcinogenic effects have been released into the environment, as a result of anthro- pogenic activities. While these compounds will forever be of concern, in the last ten years there has been increased interest in endocrine disrupting compounds (EDCs). EDCs interfere (disrupt) normal hormonal functions (development, growth and reproduction) and cause dangerous consequences to humans and wildlife, such as hermaphroditism, decreased fertility and feminization, 1 even at concentration levels as low as pg-ng/L water. As time goes on, and information on the origin, occurrence and effects of EDCs grows, the number of chemicals recognized as EDCs increases. Com- pounds that have been determined to be estrogenic include Ł Correspondence to: Dami` a Barcel ´ o, Instituto de Investigaciones Qu´ımicas y Ambientales, Jordi Girona 18-26, Barcelona 08034, Spain. E-mail: dbcqam@cid.csic.es Contract/grant sponsor: Energy, Environmental and Sustainable Development Program; Contract/grant number: ARTDEMO EVK1-CT2002-00114. Contract/grant sponsor: CICYT; Contract/grant number: BQU2002-10903-E. both natural (such as phytoestrogens, found in many plants including rice, carrots, potatoes and apples, among others) and synthetic estrogens (such as those used in birth control pills), phthalates, pesticides, dioxins, surfactants and poly- chlorinated biphenyls (PCBs). Among EDCs, progestogens, and especially estrogens, are of particular interest because of their high estrogenic potency and the extent of their use, not only as contraceptives, but also for therapeutic purposes, such as in the management of the menopausal syndrome or in diverse cancers, such as prostatic and breast cancer (see Fig. 1). The analytical determination of micropollutants in the environment is not an easy task, first, because of the complexity of the environmental matrices, and second, because of the usually extremely low concentrations of the target compounds. Thus, to achieve the sensitivity and selectivity necessary for their analysis at physiologi- cally active concentrations (pg-ng/L in water), quite labo- rious and time-consuming procedures are required. For many years, the environmental determination of steroid sex hormones has been dominated by the use of biological techniques, such as immunoassays, and gas chromatogra- phy/mass spectrometry (GC/MS). 2–4 However, recently, Copyright  2003 John Wiley & Sons, Ltd.