title: Sensitive and rapid method for amino acid quantitation in malaria biological samples using AccQ.Tag ultra performance liquid chromatography-electrospray ionization-MS/MS with multiple reaction monitoring.
abstract: An AccQ*Tag ultra performance liquid chromatography-electrospray ionization-tandem mass spectrometry (AccQ*Tag-UPLC-ESI-MS/MS) method for fast, reproducible, and sensitive amino acid quantitation in biological samples, particularly, the malaria parasite Plasmodium falciparum is presented. The Waters Acquity TQD UPLC/MS system equipped with a photodiode array (PDA) detector was used for amino acid separation and detection. The method was developed and validated using amino acid standard mixtures containing acidic, neutral, and basic amino acids. For MS analysis, the optimum cone voltage implemented, based on direct infusion analysis of a few selected AccQ*Tag amino acids with multiple reaction monitoring, varied from 29 to 39 V, whereas the collision energy varied from 15 to 35 V. Calibration curves were built using both internal and external standardization. Typically, a linear response for all amino acids was observed at concentration ranges of 3 x 10(-3)-25 pmol/muL. For some amino acids, concentration limits of detection were as low as 1.65 fmol. The coefficients of variation for retention times were within the range of 0.08-1.08%. The coefficients of variation for amino acid quantitation, determined from triplicate UPLC-MS/MS runs, were below 8% on the average. The developed AccQ*Tag-UPLC-ESI-MS/MS method revealed good technical and biological reproducibility when applied to P. falciparum and human red blood cells samples. This study should provide a valuable insight into the performance of UPLC-ESI-MS/MS for amino acid quantitation using AccQ*Tag derivatization.
authors.affiliation: Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA.
authors.forename: Jenny M
authors.initials: JM
authors.lastname: Armenta
authors.forename: Diego F
authors.initials: DF
authors.lastname: Cortes
authors.forename: John M
authors.initials: JM
authors.lastname: Pisciotta
authors.forename: Joel L
authors.initials: JL
authors.lastname: Shuman
authors.forename: Kenneth
authors.initials: K
authors.lastname: Blakeslee
authors.forename: Dominique
authors.initials: D
authors.lastname: Rasoloson
authors.forename: Oluwatosin
authors.initials: O
authors.lastname: Ogunbiyi
authors.forename: David J
authors.initials: DJ
authors.lastname: Sullivan
authors.forename: Vladimir
authors.initials: V
authors.lastname: Shulaev
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D000634:Aminoquinolines / Q000737:chemistry; D002219:Carbamates / Q000737:chemistry; D002457:Cell Extracts / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004912:Erythrocytes / Q000378:metabolism; D006801:Humans; D016778:Malaria, Falciparum / Q000378:metabolism*; D010963:Plasmodium falciparum / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: C078178:6-aminoquinolyl-N-hydroxysuccinimidyl carbamate; D000596:Amino Acids; D000634:Aminoquinolines; D002219:Carbamates; D002457:Cell Extracts