Screen Drinking Water for EPA 539 Hormones Using a Calibration Standard Specially Formulated for UCMR3

The Unregulated Contaminant Monitoring Rule 3 (UCMR3) requires monitoring of all public drinking water systems with 10,000 or more customers. For hormone screening in finished drinking water, UCMR3 lists the same seven compounds as EPA Method 539; however, the concentrations differ between the two lists.

A new certified reference material (CRM) released by Restek contains the seven hormones listed in EPA Method 539 conveniently formulated to the concentrations outlined by UCMR3 to save analysts time and labor. For those following EPA 539 guidelines, Restek also offers the same mix of hormones with the appropriate concentrations.

Compound List for Restek's EPA Method 539 CRMs

Of course, like all Restek CRMs, these standards are both manufactured and QC-tested in an ISO-accredited lab to easily satisfy ISO requirements.

www.restek.com/539-standards

Analyze a Full EPA 524.3 List Using Just Three Ampuls With New Restek EPA 524.3 Certified Reference Materials!

In support of the U.S. Safe Drinking Water Act (SDWA), Restek has formulated a complete set of EPA 524.3 reference standards for the monitoring of purgeable organic compounds in drinking water—using as few as three ampuls! This collection of certified reference materials (CRMs) also covers the seven volatile organic compounds (VOCs) included in the Unregulated Contaminant Monitoring Rule 3 (UCMR3), which requires monitoring of all public drinking water systems with 10,000 or more customers. It is also ideal for surface water and groundwater testing inside or outside the U.S.

This new set of reference standards offers a full 82-component EPA 524.3 list using as few as three ampuls to reduce prep time and chances for error or contamination. The EPA 524.3 VOA MegaMix® ampul includes the required oxygenates group for convenient ordering, while the volatile gases are prepared separately to allow replacement of shorter-life components without wasting money on the full list. Internal and surrogate standards are available independently or as a combined mix, letting analysts choose the option that works best for them. Of course, like all Restek certified reference materials (CRMs), they are manufactured and QC-tested in an ISO-accredited lab to easily satisfy ISO requirements.

Simplify your EPA 524.3 analyses and start saving today with Restek’s new reference standards set.
www.restek.com/524.3-standards

A Comprehensive Approach to Pesticide Residue Testing, Including Non-Target Analysis, for Fruits, Vegetables, and Nuts, Using QuEChERS, LC-MS/MS, and GCxGC-TOFMS

Author(s): Jack Cochran1, Julie Kowalski1, Jason Thomas1, Michelle Misselwitz1, Rebecca Wittrig2*, Andre Schreiber3

1Restek Corporation, 110 Benner Circle, Bellefonte, Pennsylvania 16823, USA
2AB SCIEX, 353 Hatch Drive, Foster City, California 94404, USA
3AB SCIEX Research and Development, 71 Four Valley Drive, Concord, Ontario, Canada L4K 4V8
*Current address: Restek Corporation, 110 Benner Circle, Bellefonte, Pennsylvania 16823, USA

Published By: Restek Corporation

Year of Publication: 2012

Link: http://www.restek.com/Technical-Resources/Technical-Library/Foods-Flavors-Fragrances/fff_FFAN1566-UNV

Abstract: Food commodities were fortified with pesticides and processed using the QuEChERS sample preparation technique. Samples were analyzed by both GCxGC-TOFMS and LC-MS/MS. The foods chosen varied in water, fat, and pigment content, so the ruggedness of QuEChERS as well as the performance of GCxGC-TOFMS and LC-MS/MS could be assessed. Commodities tested were red bell pepper, cucumber, black seedless grape, spinach, lemon, raisin, and hazelnut. Recovery values were determined by matrix-matched standards for the GC method and by solvent standards for the LC method. Evaluation of GCxGC-TOFMS and LC-MS/MS, along with the QuEChERS approach itself, was made by comparison of recovery values and incurred pesticide concentrations.

Good recoveries were obtained for most pesticides in most commodities as determined by GCxGC-TOFMS and LC-MS/MS. Sometimes GCxGC-TOFMS did not have the selectivity necessary for determining certain pesticides in the most complex samples. In this regard, dispersive SPE (dSPE) cleanup was ineffective at removing significant matrix interferences in lemon, raisin, and hazelnut extracts for some target pesticides. Corrupted LC-MS/MS quantification for some pesticides was observed, especially in lemon and hazelnut extracts, and likely resulted from ion suppression or was due to quantification by solvent-only standards. Incurred pesticide quantifications were comparable for GCxGC-TOFMS and LC-MS/MS. GCxGC-TOFMS was able to identify non-target pesticides.