Biomonitoring of Phthalate Metabolites in Human Urine using ISOLUTE® ENV+ Columns Prior to LC-MS/MS

This application note describes the extraction of nine phthalate metabolites from human urine using ISOLUTE® ENV+ solid phase extraction columns.

Introduction

Phthalates are plasticizers used in industry to adjust the mechanical (and sometimes barrier) properties of plastics in consumer products and packaging. Their ubiquitous presence in our everyday lives constantly presents threats of low level exposure through inhalation or ingestion. Thus, large biomonitoring studies including the US National Health and Nutrition Examination Survey (NHANES) have screened for phthalates since 1999. Because phthalates themselves are difficult to eliminate from sampling and processing materials, including laboratory ware and instruments, analysis of phthalates in human samples have focused on their monoester metabolites. Monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP) and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) have been constantly detected in human urine since the first NHANES survey of phthalates in 1999. Phthalates exposure has been associated with decreased anogenital distance, lower sperm count, cryptorchidism and hypospadias among other clinical endpoints in humans.