Development and validation of an LC-MS/MS method for the detection of sodium pentachlorophenolate residues on cutting boards

Abstract

Objectives: The objective of this study was to develop and validate an automated solid-phase extraction (SPE) coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the detection of sodium pentachlorophenolate (PCP-Na) residues on cutting boards. Given the potential hazards and environmental persistence of PCP-Na, a sensitive and reliable method is crucial for monitoring its residues in food contact materials to ensure consumer safety.

Methods: Wood shavings from cutting boards were extracted using 10% methanol in water, followed by purification using an automated SPE system. The eluent was concentrated, reconstituted, and analyzed by UPLC-MS/MS. An isotope-labeled internal standard was used to mitigate matrix effects, enhancing detection sensitivity. The method was validated by assessing linearity, limit of detection (LOD), limit of quantification (LOQ), recovery rates, and relative standard deviations (RSDs) across various concentration levels.

Results: The method demonstrated excellent linearity over a concentration range of 0 to 100 μg/L with a regression equation of Y = 1.035X-0.7771 and an R² of 0.9996. The LOD and LOQ were determined to be 0.4 and 1.0 μg/kg, respectively. Recovery rates ranged from 71.75% to 96.50% with RSDs between 5.19% and 16.66%. When applied to 30 market cutting board samples, PCP-Na residues were detected in 50% of the samples, with concentrations ranging from 0 to 83,990 µg/kg.

Conclusion: This study presents a robust UPLC-MS/MS method for the detection of PCP-Na on cutting boards, offering improved sensitivity and simplified sample preparation. The high detection rate in commercial samples underscores the need for stringent monitoring and regulatory measures to mitigate the exposure risk to consumers.

Keywords: Sodium pentachlorophenolate; UPLC-MS/MS; cutting boards; food safety; method validation.; solid-phase extraction.

Figure 1.

Schematic diagram of the nine-point sampling method used for collecting wood shavings from cutting boards. The sampling follows a regular and reverse plum blossom pattern, as shown in the circular and rectangular layouts. Aluminum foil is placed beneath the board to collect the samples, which are further processed for PCP-Na analysis.

Figure 2.

Calibration curve for sodium pentachlorophenolate.