Volumetric absorptive microsampling as an alternative sampling strategy for the determination of paracetamol in blood and cerebrospinal fluid

Abstract

In the field of bioanalysis, dried matrix spot sampling is increasingly receiving interest, as this alternative sampling strategy offers many potential benefits over traditional sampling, including matrix volume sparing properties. By using a microsampling strategy, e.g. volumetric absorptive microsampling (VAMS), the number of samples that can be collected from a patient can be increased, as a result of the limited sample volume that is required per sample. To date, no VAMS-based methods have been developed for the quantification of analytes in cerebrospinal fluid (CSF). The objective of this study was to develop and validate two LC-MS/MS methods for the quantification of paracetamol in dried blood and dried CSF, with both matrices sampled using VAMS. Both methods were fully validated based on internationally accepted guidelines. Paracetamol was chromatographically separated from its glucuronide and sulfate metabolites and no carry-over or unacceptable interferences were detected. The total precision (%RSD) was below 15% for all QC levels and accuracy (%bias) was below 7% (17% for the LLOQ of aqueous VAMS). The influence of the hematocrit on the recovery of blood VAMS samples appeared to be limited within the hematocrit range of 0.21 to 0.62.The blood VAMS samples were stable for 1 week if stored at 50 °C, and for at least 8 months when stored between -80 °C and room temperature. The aqueous VAMS samples were stable for at least 9 months when stored between -80 °C and 4 °C, and for 1 month when stored at room temperature.Application of the methods on external quality control material and analysis of patient samples demonstrated the validity and utility of the methods and provided a proof of concept for the analysis of CSF microsamples obtained via VAMS devices.

Dried blood microsamples: Suitable as an alternative matrix for the quantification of paracetamol-protein adducts?

“…More likely, these results could be explained by a decreased and/or more variable efficiency of the wash procedure, leading to an increased presence of APAP-Cys free in the samples after the wash procedure, resulting in a notable increase in the measured concentrations in these samples. Previous reports in literature have indicated that the extraction of small molecules from VAMS samples can be dependent on the storage condition, which is in support of this theory (Delahaye et al, 2019;Xie et al, 2018). On the other hand, the results obtained for the stability of the blood VAMS samples after storage at 50 °C are all below or approximate the lower limit of acceptance.…”

“…As we aimed at setting up a procedure for the combined determination of APAP and APAPprotein adducts, the sample preparation for the quantitation of APAP precedes the wash and digestion steps described above (Delahaye et al, 2019). In short, the VAMS sample tips are removed from the handle and extracted in a 2 mL LoBind cup with 300 µL extraction solvent (methanol/water/FA -80/20/0.01), of which 250 µL is diluted with water (0.01% FA) to a total volume of 1.0 mL and injected onto the LC-MS/MS.…”

Volumetric absorptive microsampling as alternative sampling technique for renal function assessment in the paediatric population using iohexol

“…This is still within the Table 1 Results of within-and between-day accuracy (%bias) and precision (%RSD) for QC blood VAMS samples prepared at LLOQ (0.4 µg/mL), low (2.0 µg/mL), medium (20 µg/mL) and high (200 µg/mL) iohexol concentration level. predefined − 15-15% interval, however this can be a possible sign of degradation or a storage-induced recovery issue [52]. In the study of Salvador et al, iohexol DBS were stable at room temperature up to 9 months [24].…”

Official International Association for Therapeutic Drug Monitoring and Clinical Toxicology Guideline: Development and Validation of Dried Blood Spot–Based Methods for Therapeutic Drug Monitoring

“…A difference between the fresh and the stored samples, on the other hand, might be due both to a time-dependent extraction efficiency issue and to actual instability of the target analyte. 68 However, if this difference is not observed at all HT levels, it is unlikely that analyte instability is the culprit. If the difference is observed at all HT levels, it may be worthwhile to repeat the experiment at a lower storage temperature, as this may indicate analyte instability.…”