Environmental Mass Spectrometry: Emerging Contaminants …

1 Anal. Chem. 2006, 78, 4021-4046. Environmental Mass Spectrometry: Emerging Contaminants and current Issues Susan D. Richardson National Exposure Research Laboratory, Environmental Protection Agency, Athens, Georgia 30605. Review Contents (SPME), are also becoming increasingly popular, as they allow General Reviews 4015 methods to be more automated, more rapid, and reduce error in PFOA, PFOS, and Other Perfluorinated Surfactants 4016 quantitative experiments. Large-volume injection is also becoming Pharmaceuticals, Hormones, and Endocrine 4019 more popular, as more commercial instruments accommodate this Disrupting Compounds technique, and it can allow lower detection limits due to the larger Sunscreens/UV Filters 4022 sample volume that can be injected.

2 The last two years have also Drinking Water Disinfection Byproducts 4023. seen increased applications of hydrophilic interaction chromatog- Polybrominated Diphenyl Ethers and New Flame 4027. Retardants raphy (HILIC) (usually coupled to liquid chromatography (LC)/. Benzotriazoles 4029 MS or LC/MS/MS), which uses columns with a polar end group Naphthenic Acids 4029 (such as an amino group), and retention is based on the affinity Algal Toxins 4029 of the polar analyte for the charged end group of the column Perchlorate 4031 stationary phase. This technique is ideal for separating highly polar Pesticide Degradation Products and New Pesticides 4032 analytes that are difficult to separate from the aqueous solvent Chiral Contaminants 4033 front.

3 As an example, HILIC has been shown to be useful for Microorganisms 4034. separating haloacetic acid disinfection byproducts (DBPs) for LC/. Arsenic 4035. MS/MS analysis (see drinking water disinfection byproducts Literature Cited 4036. section for details). Previous methods have used ion pairing This biennial review covers developments in Environmental reagents to separate the polar analytes from the aqueous solvent mass spectrometry over the period of 2004-2005. A few significant front in LC, but ion pairing reagents can often suppress the references that appeared between January and February 2006 are ionization of analytes of interest. HILIC allows the separation of also included.

4 Analytical Chemistry's current policy is to limit polar analytes and does not cause ionization suppression. reviews to include 100-200 significant references and to mainly Trends in new Environmental mass spectrometry research focus on new trends. As a result, as was done in the previous studies include increasing numbers of exposure and forensic 2004 Environmental Mass Spectrometry review (1), this 2006 studies. For example, there are interesting forensic investigations review will be limited in its focus to new, Emerging Contaminants of algal toxins involved in dog poisoning episodes, where mass and Environmental issues that are driving most of the current spectrometry was used to identify the algal toxins involved in these research.

5 Even with a more narrow focus, only a small fraction of incidents. Interesting human exposure studies include the use of the quality research publications could be discussed. Thus, this LC/electrospray ionization (ESI)-MS/MS to estimate exposure review will not be comprehensive, but will highlight new areas to organophosphorus pesticides by measuring their metabolites and discuss representative papers in the areas of focus. I welcome in urine. Another fascinating study involved measuring perfluo- any comments you have, in particular regarding this more narrow rooctanoic acid (PFOA) in food packaging where perfluorinated focus, whether you find it more (or less) useful than a broader chemicals (PFCs) are commonly used.

6 Of the different food approach packagings investigated (including hamburger wrappers, french Numerous abstracts were consulted before choosing the best fry boxes, paper plates, dental floss, etc.), microwave popcorn bags ones to present here. Abstract searches were carried out using were shown to leach extremely high levels of PFOA into the current Contents, and in many cases, full articles were obtained. popcorn, such that consuming one bag of popcorn per month The overall trends in analytical methods include an increasing could account for as much as 20% of the average levels of PFOA. use of time-of-flight (TOF)-mass spectrometry (MS) and quadru- found in human blood (see section on PFOA, perfluorooctane- pole (Q)-TOF-MS for structural elucidation and compound con- sulfonate (PFOS), and perfluorinated surfactants for more details).

7 Firmation. TOF-MS and Q-TOF-MS provide increased resolution In addition, many of the new exposure studies are focusing on capability (typically 10 000-12 000 resolution), which allows chiral Contaminants , where enantiomer-specific uptake and me- precise empirical formula assignments for unknowns and also tabolism can occur. For example, papers include the measurement provides added confidence for positive identifications in quantita- of chiral toxaphene congeners in eggs from laying hens and the tive work. This benefit of TOF-MS and Q-TOF-MS can be seen enantioselective elimination of toxaphene metabolites in fish. particularly in the sections on algal toxins and pesticide degrada- As water is becoming more scarce in different regions of the tion products.

8 On-line preconcentration methods, typically with United States, there has been a substantial increase in the number on-line solid-phase extraction (SPE) or solid-phase microextraction of studies involving reclaimed water. Examples include studies Not subject to Copyright. Publ. 2006 Am. Chem. Soc. Analytical Chemistry, Vol. 78, No. 12, June 15, 2006 4021. Published on Web 05/11/2006. involving the measurement of pharmaceuticals and DBPs in These continue to be intense areas of research. The class of reclaimed water. In addition, as degradation products of pesticides Emerging contaminant experiencing the most rapid growth in have become increasingly important, pharmaceutical degradates research is the perfluorinated surfactants.

9 They were included for (also called metabolites) are also becoming important. Improved the first time in the last Environmental mass spectrometry review analytical techniques are enabling their identification and mea- (2004), and as studies continue to show their widespread presence surement in Environmental samples, and new studies address their in human blood and biota, and health effects issues with them fate in wastewater and drinking water treatment. are uncovered, they remain a high priority for the Environ- Six new categories of Emerging Contaminants are added to this mental Protection Agency (EPA). Environmental mass spectrometry review this year: new bromi- nated/chlorinated flame retardants (beyond polybrominated di- GENERAL REVIEWS.)

10 Phenyl ethers (PBDEs)), sunscreens/UV filters, contaminant - This section includes general reviews relating to Environmental DBPs, benzotriazoles, naphthenic acids, and arsenic mode of mass spectrometry. Reviews that relate to specific areas ( , action studies. Interesting new research by Hites' group has pharmaceuticals, DBPs, or microorganisms) can be found in those uncovered new brominated/chlorinated flame retardants that were specific sections. Many reviews have been published over the last not previously known. One of these, Dechlorane Plus (bis- two years that relate to Environmental mass spectrometry, and a (hexachlorocyclopentadieno)cyclooctane) has been on the market few focus specifically on Emerging Contaminants .