Phthalate Ester Metabolites

Phthalates, or dialkyl or alkyl aryl esters of 1,2-benzenedicarboxylic acid, are a family of compounds used in a variety of applications such as plasticizers in polyvinyl chloride, and additives in lubricant, paints, pesticides, and personal care products. Phthalates are metabolized into phthalate esters and excreted in urine either free, or conjugated with glucoronide.

Since 2006, we have provided low-level measurement of monophthalate esters and their conjugates in aqueous samples by isotope-dilution LC-MS/MS.  Our target lists and reporting limits are designed for compatibility with data generated by the CDC NHANES program and has been used in multiple epidemiological studies. Our method includes critical QC checks on deconjugation success for increased data accuracy.

Targets (Reporting limits < 1 ng/mL)
Monomethyl phthalate (mMP)
Monoethyl phthalate (mEP)
Monobutyl phthalate (MBP) (sum of mono-n-butyl and mono-iso-butyl phthalate)
Monobenzyl phthalate (mBzP)
Mono-2-ethylhexyl phthalate (mEHP)
Mono-(2-ethyl-5-oxohexyl) phthalate (DEHP Metabolite VI) (mEOHP)
Mono-(2-ethyl-5-hydroxyhexyl) phthalate (DEHP (Metabolite IX) (mEHHP)
Mono-cyclohexyl phthalate (MCHP)
Mono-(3-carboxypropyl) phthalate (MCPP)
Mono-iso-nonyl Phthalate (MiNP)

Project Spotlight

Phthalates in follicular fluid after invitro fertilization (IVF)

Tubes labeled with bar codes with blood samples inside

Scientists from the Advanced Fertility Center of Texas and the Hospital of Rhode Island used SGS AXYS measurements of phthalate ester metabolites and Bisphenol A in women undergoing IVF.  The objective of their study was to determine whether exposure to medical plastics during an IVF cycle would result in any accumulation of endocrine-disrupting phthalates and bisphenol A. Krotz et al 2012 reported that the levels measured in follicular fluid were 200–1000 fold less than the minimum levels reported to cause reproductive toxicity.