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.