title: Comparison of different sample preparation methods for platinum determination in cultured cells by graphite furnace atomic absorption spectrometry.
abstract: BACKGROUND
  Platinum-based agents are widely used in chemotherapy against solid tumors and insufficient intracellular drug accumulation is one of the leading causes of platinum resistance which is associated with poor survival of tumor patients. Thus, the detection of intracellular platinum is pivotal for studies aiming to overcome platinum resistance. In the present study, we aimed to establish a reliable graphite furnace atomic absorption spectrometry (GFAAS)-based assay to quantify the intracellular platinum content for cultured cells.
  
  
  METHODS
  Several most commonly applied cell preparation methods, including 0.2% HNO3, 0.2% Triton X-100, concentrated nitric acid, RIPA combined with concentrated nitric acid and hydroxide, followed by GFAAS for platinum detection were compared in ovarian, cervical and liver cancer cell lines to obtain the optimal one, and parameters regarding linearity, accuracy, precision and sensitivity were evaluated. Influence of other metals on platinum detection and the storage conditions of samples were also determined.
  
  
  RESULTS
  The treatment of cells with 0.2% HNO3was superior to other approaches with fewer platinum loss and better repeatability. The recovery rate and precision of this method were 97.3%-103.0% and 1.4%-3.8%, respectively. The average recoveries in the presence of other metals were 95.1%-103.1%. The detection limit was 13.23 ug/L. The recovery rate of platinum remained acceptable even in cell samples stored in -20 °C or -80 °C for two months.
  
  
  CONCLUSIONS
  After comparison, we found that 0.2% HNO3was optimal for intracellular platinum quantification based on GFAAS, which presented values compatible with that of inductively-coupled plasma mass-spectrometry (ICP-MS), and this is partially attributed to the simplicity of this method. Moreover, the assay was proved to be accurate, sensitive, cost-effective and suitable for the research of platinum-based antitumor therapy.
authors.affiliation: Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Man
authors.initials: M
authors.lastname: Xiao
authors.affiliation: Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Zaiju
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Cai
authors.affiliation: Department of Obstetrics and Gynecology, Air Force General Hospital, PLA, Beijing, China.
authors.forename: Jinghui
authors.initials: J
authors.lastname: Jia
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Yuzeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Dong
authors.affiliation: Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Zehua
authors.initials: Z
authors.lastname: Wang
keywords: Cells; GFAAS; Method; Platinum