Disposable pipette extraction phase based on styrene–divinylbenzene/pernigraniline composite, applied for dexamethasone determination in synovial fluid by HPLC with UV detector

Abstract

A reliable method using disposable pipette extraction (DPX) based on composite of pernigraniline and styrenedivinylbenzene (Sty-DVB) copolymer was applied to the analysis of dexamethasone in synovial fluid using highperformance liquid chromatography and ultraviolet (UV) detector (HPLC-UV). DPX variables, namely, number of draw/eject cycles for extraction or desorption, sample pH, volume, and desorption solvent, were optimized to establish the best sorption equilibrium and analysis time. The highest extraction efficiency value was obtained with 50 μL of synovial fluid mixed with 1950 μL of water, in five cycles of 300 μL of sampling, followed by liquid desorption of the drug with 300 μL of methanol in three cycles. The developed method demonstrated a linear response over the range from 10 to 100 ng/mL, with R 2 = 0.993. The limit of quantification (LOQ) was 10 ng/mL. Based on the validation results, the proposed method can be a useful tool to detect dexamethasone levels in synovial fluid.

A review of micro-solid-phase extraction techniques and devices applied in sample pretreatment coupled with chromatographic analysis

“…Extraction efficiency is not affected by channeling at any flow rate. Extractions can be fully automated, reducing sample manipulation, and thus improving precision and sample throughput [80]. Figure 4 illustrates the disposable pipette extraction process.…”

Polyaniline‐silica doped with oxalic acid as a novel extractor phase in thin film solid‐phase microextraction for determination of hormones in urine

“…PAni-based materials were recently reported for use in sample preparation. For example, PAni and poly(styreneco-divinylbenzene)-based composites were synthesized and used as the extractor phase for disposable pipette extraction to determine fluoxetine and norfluoxetine from plasma samples [10] and dexamethasone in synovial fluid [11]. Ghiasvand et al designed and fabricated sulfonated graphene-PAni nanocomposite as a fiber of solid-phase microextraction (SPME) for the analysis of nicotine in solid samples [12].…”

“…PAni‐based materials were recently reported for use in sample preparation. For example, PAni and poly(styrene‐co‐divinylbenzene)‐based composites were synthesized and used as the extractor phase for disposable pipette extraction to determine fluoxetine and norfluoxetine from plasma samples [10] and dexamethasone in synovial fluid [11]. Ghiasvand et al.…”

Determinação de pesticidas em alimentos derivados da cana-de-açúcar por LC-MS/MS empregando DPX como técnica de preparo de amostra

“…A passagem de amostra pela ponteira é conhecida como ciclo, ou seja, cada aspiração/dispensa da amostra constitui um ciclo. Alguns trabalhos [88][89][90][91] indicam que realizar este processo várias vezes aumenta a sorção dos analitos à fase extratora, resultando em maiores recuperações.…”