title: Development and validation of a measurement procedure based on ultra-high performance liquid chromatography-tandem mass spectrometry for simultaneous measurement of β-lactam antibiotic concentration in human plasma.
abstract: BACKGROUND
  The administration of β-lactam antibiotics in continuous infusion could let optimize the pharmacokinetic/pharmacodynamic parameters, especially in the treatment of serious bacterial infections. In this context, and also due to variability in their plasmatic concentrations, therapeutic drug monitoring (TDM) may be useful to optimize dosing and, therefore, be useful for the clinicians.
  
  
  METHODS
  We developed and validated a measurement procedure based on ultra-high performance liquid chromatography-tandem mass spectrometry for simultaneous measurement of amoxicillin, ampicillin, cloxacillin, piperacillin, cefepime, ceftazidime, cefuroxime, aztreonam and meropenem concentrations in plasma. The chromatographic separation was achieved using an Acquity®-UPLC® BEH™ (2.1×100mm id, 1.7μm) reverse-phase C18column, with a water/acetonitrile linear gradient containing 0.1% formic acid at a 0.4mL/min flow rate. β-Lactam antibiotics and their internal standards were detected by electrospray ionization mass spectrometry in multiple reaction monitoring mode.
  
  
  RESULTS
  Chromatography run time was 7.0min and β-lactam antibiotics eluted at retention times ranging between 1.08 and 1.91min. The lower limits of quantification were between 0.50 and 1.00mg/L. Coefficients of variation and relative bias absolute values were <13.3% and 14.7%, respectively. Recovery values ranged from 55.7% to 84.8%. Evaluation of the matrix effect showed ion enhancement for all antibiotics. No interferences or carry-over were observed.
  
  
  CONCLUSIONS
  Our measurement procedure could be applied to daily clinical laboratory practice to measure the concentration of β-lactam antibiotics in plasma, for instance in patients with bone and joint infections and critically ill patients.
authors.affiliation: Laboratori Clínic Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain. Electronic address: raulr@bellvitgehospital.cat.
authors.forename: Raül
authors.initials: R
authors.lastname: Rigo-Bonnin
authors.affiliation: Infectious Diseases Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain; Spanish Network for Research in Infectious Diseases (REIPI RD12/0012), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Alba
authors.initials: A
authors.lastname: Ribera
authors.affiliation: Laboratori Clínic Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Ariadna
authors.initials: A
authors.lastname: Arbiol-Roca
authors.affiliation: Pharmacy Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Cobo-Sacristán
authors.affiliation: Pharmacy Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Ariadna
authors.initials: A
authors.lastname: Padullés
authors.affiliation: Infectious Diseases Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain; Spanish Network for Research in Infectious Diseases (REIPI RD12/0012), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Òscar
authors.initials: Ò
authors.lastname: Murillo
authors.affiliation: Infectious Diseases Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain; Spanish Network for Research in Infectious Diseases (REIPI RD12/0012), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Shaw
authors.affiliation: Intensive Care Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Granada
authors.affiliation: Intensive Care Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Xosé L
authors.initials: XL
authors.lastname: Pérez-Fernández
authors.affiliation: Microbiology Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain; Spanish Network for Biomedical Research in Respiratory Diseases (CIBERES CB06/060037), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Fe
authors.initials: F
authors.lastname: Tubau
authors.affiliation: Laboratori Clínic Department, IDIBELL, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Alía
mesh_terms: D000900:Anti-Bacterial Agents / Q000097:blood*; D001774:Blood Chemical Analysis / Q000379:methods*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D016014:Linear Models; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013997:Time Factors; D047090:beta-Lactams / Q000097:blood*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams
keywords: Human plasma; Protein precipitation; Therapeutic drug monitoring; UHPLC-MS/MS; β-Lactam antibiotics