The increase in the number of cases of breast cancer required the development of new pharmaceutical formulas, letrozole being one of the drugs used for this purpose. Treatment with this drug requires detection and monitoring of these substances1. In the doping control of athletes, letrozole is a forbidden substance. Letrozole is included in the Prohibited List of World Anti-Doping Agency (WADA) at the Sections Hormone and Metabolic modulators, Aromatase inhibitors, selective estrogen receptor modulators (SERMs) and other anti-estrogenic substances2,3. For the analysis of these compounds, the technique of choice is the liquid-chromatography tandem mass spectrometry technique (LC-MS/MS). Due to the metabolism of the substance, it is required the analysis of both the compound and the metabolite bis-(4- cyanophenyl)methanol by LC-MS/MS. In the WADA Technical Document TD2018MRPL, the Minimum Required Performance Levels for Detection and Identification of Non-threshold Substances (MRPL) for anti-estrogenic substances is 20 ng/mL2,4. This paper discloses the optimization of the LC-MS/MS detection parameters of letrozol and letrozol metabolite.
[1]
H. Oberacher,et al.
Development and validation of a liquid chromatography–tandem mass spectrometry method for the simultaneous quantification of tamoxifen, anastrozole, and letrozole in human plasma and its application to a clinical study
,
2010,
Analytical and bioanalytical chemistry.
[2]
I. Smith.
Letrozole versus tamoxifen in the treatment of advanced breast cancer and as neoadjuvant therapy
,
2003,
The Journal of Steroid Biochemistry and Molecular Biology.
[3]
M. Mazzarino,et al.
A screening method for the simultaneous detection of glucocorticoids, diuretics, stimulants, anti-oestrogens, beta-adrenergic drugs and anabolic steroids in human urine by LC-ESI-MS/MS
,
2008,
Analytical and bioanalytical chemistry.