Interlaboratory comparison for urinary trans, trans-muconic acid testing in Rayong province

Abstract

Introduction: The objective of this study was to assess reliability of urinary trans, trans-muconic acid (t,t-MA) analysis by high performance liquid chromatography (HPLC) technique among three laboratories in Rayong province.
Method: We conducted the interlaboratory comparison among three laboratories for t,t-MA testing via two steps. Step one was the preparation phase to settle the agreement and protocol. Step two was the comparison: step 2.1 the comparative HPLC-analysis of blank and spiked urines and step 2.2 the comparative HPLC-analysis of 30 urine samples obtained from subjects. Subjects were gas station workers in Rayong province.

Result: The result obtained from step 2.1 showed the good percentage of recovery and comparable results. Non significant differences between each pair of the 3 laboratories and high intra-class correlation coefficients in step 2.2 implied good reliability of 3 laboratories.

Discussion and Conclusion: This interlaboratory comparison could be considered an initiative for external quality assurance of this
laboratory testing