Development and validation of LC-MS/MS method for the determination of Ochratoxin A and its metabolite Ochratoxin α in poultry tissues and eggs

ABSTRACT

The objective of this study was to develop a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the determination of Ochratoxin A (OTA) and Ochratoxin α (OTα) in poultry tissues and eggs. The two toxins were extracted by a mixture of acetonitrile/water, purified with a reversed phase C18 solid phase extraction column (SPE) and determined by LC-MS/MS. The LC-MS/MS method performances were evaluated in terms of linearity in solvent and in matrix (ranged from 0.5 to 15.10 µg L⁻¹ for OTA and from 0.60 to 17.85 µg L⁻¹ for OTα), limit of detection (LOD), limit of quantitation (LOQ), specificity, accuracy and precision in repeatability conditions. Recovery experiments were performed by spiking poultry liver, kidney, muscle and eggs around 1 µg kg⁻¹ and 10 µg kg⁻¹. LODs were 0.27 and 0.26 µg kg⁻¹ while LOQs were fixed at 1.0 and 1.2 µg kg⁻¹ for OTA and OTα, respectively. Main recoveries for OTA ranged from 82 to 109% and for OTα ranged from 55 to 89%. The values of within-laboratory relative standard deviation (RSD_r) were equal to or below 20%. Considering the results obtained and that all analytical performance criteria were fulfilled, the new extraction and purification method developed for OTA and OTα determination in animal tissues and eggs was found appropriate for control laboratories and research activities designed to ensure food safety.

KEYWORDS:

• Mass-spectrometry
• poultry tissues
• eggs
• method validation
• OTA
• OTα

Acknowledgments

Financial support for this work was provided by Italian Ministry of Health, Department of Veterinary Public Health and Food Safety. Rome Italy.

The authors are grateful to Salwa Jazmati for English text revision.

Supplementary materials

Table 1S. Working solutions preparation.

Table 2S. Gradient conditions for OTA and OTα chromatographic run.

Table 3S. Default recommended maximum permitted tolerances for relative ion intensities.

Table 4S. Experimental t-values.

Additional information

Funding

This work was supported by the Italian Ministry of Health [RC IZSUM 01/2006].