A quantitative HPLC–MS method for the simultaneous determination of testosterone, 11-ketotestosterone and 11-β hydroxyandrostenedione in fish serum

Reproductive endocrinology of Syngnathidae

“…Future endocrine studies must focus on syngnathid species with well‐characterized reproductive biology, incorporating both laboratory and field sampling to establish the identity of the principal endogenous hormones and define physiological ranges for experimental manipulations. Sensitive immunoassays for multiple hormones in small volumes, such as high and ultra‐performance liquid chromatography followed by mass spectrometry (Blasco et al , 2009), should be validated for syngnathid peptide and steroid hormones. Steroid measurement in fish holding water may also be a practical, non‐invasive method for small or rare syngnathids (Scott & Ellis, 2007) or for behaviour studies where repeated sampling of one individual is required (Scott et al , 2008; Kidd et al , 2010).…”

Quantification of 2-hydrazinopyridine derivatized steroid hormones in fathead minnow (Pimephales promelas) blood plasma using LC-ESI+/MS/MS

“…The average 11-KT concentration (19.11 ng/ml) measured in male fish in this study were in range with those reported in other studies using liquid chromatography and mass spectrometry. For example, in cyprinid small-fish species such as goldfish and fathead minnow, plasma 11-ketotestosterone in male fish have been reported from 19.38 to 32.2 ng/ml [38,39]. Elevated concen- Table 2 Mean total percentage precision, accuracy and signal-to-background values for (a) 17␣OH-pregnenolone, (b) progesterone, (c) 11-ketotestosterone (11-KT), (d) 11-deoxycortisol (11-DC) and (e) 17␣,2␤-dihydroxypregnenone (17,20-DP).…”

“…Within the environmental sciences, LC-MS/MS has most commonly been used for the identification and quantitation of anthropogenic contaminants (including various steroid hormone analogues) in solid and liquid environmental matrices [30][31][32][33][34][35][36][37]. A more recent extension of such analyses has included the quantification of steroid hormones in blood plasma of small fish species, such as goldfish (Carassius auratus) and fathead minnow (Pimephales promelas) [38,39]. Despite these recent applications, only a limited number of steroid hormones have been quantified thus far.…”

Lethal and sublethal effects of cypermethrin and methoxyfenozide on the larvae ofRachiplusia nu(Guenee) (Lepidoptera: Noctuidae)

“…Separation was done in a C18 column of 15 cm  4.6 mm inner diameter using acetonitrile:water 80:20, at 0.8 mL/min, with the detection single ion monitor positive mode at 432 umas ([M þ NH 4 ] þ ) in an LC-MS Agilent 1100 LC system (Agilent Technologies Inc., USA) equipped with a binary pump and a diode array detector, and coupled with an MSD VL quadrupole (Agilent Technologies, USA) with an electrospray ionization interface set at 150 eV, using nitrogen to assist nebulization, at 300 C. A Rheodyne 7725i injector with a 20 mL loop was used. Data acquisition and analysis were performed using an LC/MSD Agilent ChemStation (Blasco et al 2009). …”