Long-term stability of synthetic cathinones in dried blood spots and whole blood samples: a comparative study

Author(s)

da Cunha, Kelly Francisco ^[1] ; Eberlin, Marcos Nogueira ^[2] ; Costa, Jose Luiz ^{[3, 1]}

Affiliation

^[1] Univ Estadual Campinas, Fac Med Sci, Campinas Poison Control Ctr, BR-13083859 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Inst Chem, ThoMSon Mass Spectrometry Lab, BR-13083970 Campinas, SP - Brazil

^[3] Univ Estadual Campinas, Fac Pharmaceut Sci, BR-13083859 Campinas, SP - Brazil

• Document type: Journal article
• Source: Forensic Toxicology; v. 36, n. 2, p. 424-434, JUL 2018.
• Web of Science Citations: 1

Abstract

The long-term stability of four synthetic cathinones in dried blood spots (DBS) were tested and compared with those of whole blood samples. A method to determine four cathinones (pentylone, butylone, mephedrone and benzedrone) in DBS was developed and validated. For comparison, the traditional liquid-liquid extraction for the same analytes in whole blood was also performed. The calibration curve was found to be linear over 25-1000 ng/mL for DBS samples, with a limit of quantification (LOQ) at 25 ng/mL. The interday imprecision and bias results {[}up to 7.1% relative standard deviation (RSD) and 5.8%, respectively] were much lower than the maximum data recommended by SWGTOX guidelines. The validation results were similar to those of whole blood samples, which showed interday imprecision and bias results of up to 8.1%RSD and 12.3%, respectively, with a linear calibration curve between 10 and 1000 ng/mL and LOQ of 10 ng/mL. A stability study to compare the degradation rate between both matrices at three storage temperatures {[}room temperature (25 A degrees C), 4 and - 20 A degrees C] and during 90 days proved the poor stability of cathinones in whole blood, where the methylenedioxy cathinones displayed better stability than those with ring substituents. DBS allowed detection of synthetic cathinones after much longer periods than in whole blood samples. DBS proved, therefore, to be an useful alternative technique to store blood samples. Extraction of DBS is easy and analytes remain stable for much longer periods. (AU)

• FAPESP's process: 15/10650-8 - Stability of medicines, drugs of abuse and pesticides in dried blood spots (DBS), and its application in forensic toxicology
• Grantee: José Luiz da Costa
• Support Opportunities: Regular Research Grants