Dear Marmam,

My co-authors and I are pleased to announce the publication of our paper:

Nanospray liquid chromatography/tandem mass spectrometry analysis of steroids from gray whale blubber.

Mary Hayden, Ruchika Bhawal, John Escobedo, Clinton Harmon, Todd M. O’Hara, David Klein, Susan San-Francisco, Masoud Zabet-Moghaddam and

Céline A. J. Godard-Codding

Rapid Communications in Mass Spectrometry 2017, 31, 1088?C1094

Abstract:

RATIONALE: Analysis of steroids from precious blubber biopsies obtained from marine mammals, especially endangered

species, can provide valuable information on their endocrine status. Challenges with currently used ELISA methodology

include lack of absolute quantitation and incompatibility with multiple steroids analysis due to limited biopsy mass.

Development of a sensitive, accurate analytical method for this purpose is critical.

METHODS: A nanospray liquid chromatography/tandem mass spectrometry (nanoLC/MS/MS) method was validated

for sensitive, specific and quantitative analysis of three steroid hormones, without derivatization, extracted from 50 mg

blubber samples. Data was acquired with an LTQ XL ion trap mass spectrometer in positive ion mode, using single

reaction monitoring. All three steroids were analyzed in a single run. Cholic acid was used as a surrogate internal standard

for quantitation due to its steroidal structure and lack of measurable endogenous levels in blubber.

RESULTS: The lowest limits of quantitation for progesterone, testosterone, and hydrocortisone were significantly

improved compared to previous studies using conventional LC/MS/MS. The lowest limit of detection was 7 fg/μL using

a 1 μL injection volume. Calibration curves for steroid quantification showed good linearity (r²>0.99) between 14 and 3620

fg/μL, and accuracy was <20% for interday and<10% for intraday. After validation, the method was successfully applied

to quantification of steroids in gray whale blubber samples.

CONCLUSIONS: The nanoLC/MS/MS method is more sensitive than traditional LC/MS/MS for steroid analysis. It is

also compatible with other important biopsy analyses due to its small blubber mass requirement. This will benefit the

John Wiley & Sons, Ltd.

The paper is available here: http://onlinelibrary.wiley.com/doi/10.1002/rcm.7884/full

Please make any requests for copies to: mary.hayden@ttu.edu

Cheers,

Mary J Hayden

Ph.D. Candidate

Department of Environmental Toxicology

The Institute of Environmental and Human Health

1207 S. Gilbert Dr. | Lubbock, TX 79416

Ph: 806-885-4567