Potential sources of background contaminants in solid phase extraction and microextraction

Abstract

A study to identify the sources of background contamination from SPE, using a C-18 sorbent, and solid-phase microextraction (SPME), using a 70 microm carbowax/divinylbenzene (CW/DVB) fiber, was carried out. To determine the source of contamination, each material used in the procedure was isolated and examined for their contribution. The solid-phase column components examined were: sorbent material and frits, column housings and each solvent used to elute analytes off the column. The components examined in the SPME procedure were: SPME fiber, SPME vials, water (HPLC grade), and salt (sodium chloride) used to increase the ionic strength. The majority of the background contaminants from SPE were found to be from the SPE sorbent material and frits. The class of contaminants extracted during a blank extraction were phthalates and other plasticizers used during the manufacturing process. All had blank levels corresponding to measured concentrations below 2 ng/ mL, except for undecane, which had a concentration of 5.4 ng/mL. The most prevalent contaminants in the SPME blank procedure are 1,9-nonanediol, a mixture of phthalates and highly bis-substituted phenols. All the concentrations were below 2 ng/mL, with the exception of bis (2-ethylhexyl) phthalate, which had concentrations ranging from 5 to 20 ng/mL.

Measurement of bisphenol A, bisphenol A ß-d-glucuronide, genistein, and genistein 4′-ß-d-glucuronide via SPE and HPLC-MS/MS

“…While blank controls are always important, they are especially vital when analyzing ubiquitous compounds such as BPA, which is known to be prevalent in many common laboratory supplies and other materials required for SPE and HPLCMS/MS analysis due to its use as a plasticizer [33]. Efforts were made to minimize the contact of samples with plastics, and plasticware was replaced by glassware wherever possible.…”

Assessing exposure to phthalates – The human biomonitoring approach

“…These circumstances hamper the reliable quantification of phthalates in real-life scenarios. As a result, all ambient monitoring data and all data in general related to measurements of low levels of phthalate diesters have to be interpreted with utmost caution because of possible external contamination [68][69][70].…”

Inhibition of Genistein Glucuronidation by Bisphenol A in Human and Rat Liver Microsomes

“…SPE blank controls contained high purity water in place of standard solutions and were processed alongside samples during SPE using all of the same supplies and reagents. The use of blank controls is especially important when analyzing ubiquitous compounds such as BPA, which is known to be prevalent in numerous laboratory supplies because of its use as a plasticizer (Stiles et al, 2007). The use of plastics was minimized wherever possible, such as using glass incubation vials instead of plastic, in an effort to reduce contamination with BPA.…”