Comparison of Different Urine Pretreatments for Biological Monitoring of Pyrethroid Insecticides

Abstract

During a cross-validation practice of urinary analysis of pyrethroid insecticide metabolite (3-phenoxybenzoic acid, 3-PBA) by two laboratories (Lab A and Lab B), difference in 3-PBA concentration was noticed. The analytical methods used in the exercise were enzymatic deconjugation (glucuronidase/sulfatase) followed by solid phase extraction and isotope dilution LC-MS-MS determination (Lab A) and acidic deconjugation followed by liquid-liquid extraction and gas chromatography-mass spectrometry determination (Lab B). A significant difference was found for one of the five samples: lower value was obtained in Lab A. Use of acidic deconjugation in Lab A resulted in comparable value with the analytical result for this sample originally obtained in Lab B. The comparison was extended to 42 urine samples taken from Japanese males in Lab A by using the two different deconjugation methods and LC-MS-MS determination. Significantly lower value was obtained for enzymatic deconjugation in some of the 42 urine samples. The results suggested the presence of other conjugated species of 3-PBA than glucuronide and sulfate in human urine. Although the overall agreement between the values obtained by the deconjugation methods was fair, it appears that urine samples should be pretreated by acidic deconjugation for the analysis in biological monitoring of pyrethroid exposure.

Identification by Liquid Chromatography–Tandem Mass Spectrometry and Liquid Chromatography–Quadrupole Time-of-Flight Mass Spectrometry of the Contributor to the Thyroid Hormone Receptor Agonist Activity in Effluents from Sewage Treatment Plants

“…It has been suggested that TRIAC is efficiently glucuronidated in human and rat. , Therefore, the conjugate in the STP samples (Site3_May_IF and EF) was evaluated. The STP samples were deconjugated according to previous studies − and evaluated by comparing the TRIAC concentration in raw (no enzyme treatment) and enzyme-treated samples. TRIAC was not detected in both raw and enzyme-treated samples of May_IF.…”

Streptavidin-biotin system-mediated immobilization of a bivalent nanobody onto magnetosomes for separation and analysis of 3-phenoxybenzoic acid in urine

“…The biomarker 3-PBA is commonly found in urine in various forms, including free, glycine-conjugated, glucuronideconjugated, sulfate-conjugated, and unidentied conjugated forms. 6,7 It is well known that acidic deconjugation is an important pretreatment step for the biological monitoring of pyrethroid exposure in urine samples. This study involved the construction of BMP-SA-Biotin-Nb2 complexes with high specicity and sensitivity to 3-PBA under stringent conditions.…”

“…5 It can effectively indicate exposure to pyrethroid insecticides such as cypermethrin, deltamethrin, permethrin, cyhalothrin, fenvalerate, fenpropathrin, sumithrin, and other potential compounds. 6,7 Urinary concentrations of 3-PBA provide valuable information about the level of exposure to these insecticides, helping to assess potential health risks associated with their widespread use in agriculture and forestry. By monitoring 3-PBA levels in urine, researchers and public health officials can better understand the extent of pyrethroid exposure in populations and implement appropriate measures to mitigate potential adverse effects on human and environmental health.…”

“…Studies have shown that following exposure to pyrethroids, 3-PBA appears in urine in various forms, including free, glycineconjugated, glucuronide-conjugated, sulfate-conjugated, and unidentied conjugated forms. 6,7 The presence and proportion of these forms can vary among individuals due to unique physiological factors. Previous urine biomonitoring research utilized glucuronidase/sulfatase enzymes for deconjugation, which may lead to underestimation of 3-PBA levels as they only release the compound from its conjugated forms.…”

In silico deconjugation of glucuronide conjugates enhances tandem mass spectra library annotation of human samples

“…Therefore, during sample preparation, glucuronides are often converted by enzymatic or acidic hydrolysis to the corresponding aglycone [8,9]. The application of such pre-treatment steps, in addition to the disadvantage of being work-intensive and reported to be less reproducible [10,11], may also lead to unexpected and unintended alterations in the sample composition [12]. Some conjugates produce a specific neutral loss (NL) in tandem mass spectrometry [13], which can be utilized as an analytical tool to detect those species [6].…”