ABSTRACT
Objective To introduce a practical high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS)method for the detection of seven growth hormone-releasing peptides (GHRPs)including GHRP-1,GHRP-2,GHRP-4,GHRP-5,GHRP-6,Hexarelin and Alexamorelin and two growth hormone secretagogues(GHS)including anamorelin and ipamorelin,and study the stability of these nine substances in the human urine.Method The urine samples were purified and extracted by a solid phase extraction procedure using Oasis(R) WCX column.The urine was first centrifuged and taken out 1 mL into a small column,cleaned by 5％ NH4OH and 20％ CH3CN respectively,eluated using the mixture of water and acetomitrile(1/3)with 2％ formic acid,blow-dried in the nitrogen at 35℃ and finally redissolved to be injected into the LC-MS/MS.Result The limits of detection were between 0.01～0.5 ng/mL accordingly.The spiked recoveries at the low concentration(1 ng/mL),medium concentration(2 ng/mL)and high concentration(10 ng/mL)ranged between 40％ and 76％.The intra-and interday precisions of the target substances at these three concentrations were all less than 15％.The indoor temperature,refrigeration condition and multigelation were observed to have significant impact on the anamorelin,GHRP-2,GHRP-4 and GHRP-5.Conclusion The method established in this study is simple,and its specificity and sensitivity meets the international standard and technical documents for laboratories set up by the Wworld Anti-Doping Agency.It has been applied in our routine work.Multigelation should be avoided in the transport,detection and long-term laboratory storage of urine samples.
ABSTRACT
A method was evaluated for determination of twenty-one doping (including nandrolone, boldenone and methandienone) in human urine by gas chromatography-high resolution mass spectrometry. Samples were prepared by liquid-liquid extraction, concentrated, TMS derivatization and limit of detection at ng x mL(-1) by MID/GC/HRMS. According to the code of the World Anti-Doping Agency (WADA), precision and recoveries of the procedure were evaluated by replicate analysis (n = 6), the recoveries in the range of 66%-103%, with the RSD below 10.0%. The precision within the day of the method with three different concentrations was also determined RSD were less than 9.5%, 10.0% and 9.7%.
ABSTRACT
Objecave To develop a sensitive and specific LC-MS/MS method for determination of testolactone in human urine.Methods A C_(18 )column(2.1×50mm,3.5μm) was used.The mobile phase Was a mixture of acetonitrile and the buffer solution(ammonium acetate-water solution adjusted with formic acid to pH 3.5)at a flow rate of 0.5ml/min.A mass spectrometer equipped with electrospray ionization source was used as a detector and operated in the positive mode.In multiple reaction monitoring(MRM)mode,the ion transitions of m/z 301→121 and m/z 301→25 was used to qualify and quantify the testolactone,respectively.Results Chromatograms showed no endogenous interfering peaks with the urine blank sample.Each analysis was completed within 7min The calibration wag linear in the concentration range within 0.1～50μg/ml.The intra-batch and inter-batch RSD were less than 10%.The recovery rate of the extraction was about 60%.Conclusions The method is proved to meet the requirements of WADA and be suitable for routine screening.
ABSTRACT
In this article,anti-doping techniques including sample preparation,isolation and analysis,were reviewed.On-line solid-phase extraction with column-switching technique and High through rapid analysis were also discussed.