Replacing water by air as intermediate phase resulted in an increase in sampling rates up to a factor of 6. Decreasing sampling rates were ob- served for the 5-ring PAHs, which showed a decrease in sampling rate by a factor of 2–3 as a result of their very low K aw values (o3 Â 10 À5 ). The use of 1-octanol as intermediate phase resulted in an approximately 20-fold increase in sampling rates compared with water as intermediate phase [5]. It should be noted again, however, that reducing the transfer resistances of the internal phases, enhances the relative importance of the mass-transfer resistance of the WBL (Eq. (7.5)), and hence the sen- sitivity of the sampler to changes in flow conditions. 7.9 CALIBRATION 7.9.1 Static exposure design In the experimentally convenient static exposure scenario, passive samplers are exposed in a single volume of contaminated water. This method has been used in the past for determining bioaccumulation factors and uptake rates of contaminants by fish and mussels. The evolution of aqueous concentrations in the exposure water is given by [58–60] C w ¼ C w0 1 þ K sw V s V w exp À 1 þ K sw V s V w R s t K sw V s 1 þ K sw V s V w (7.38) where C w0 is the aqueous co ncentr ation a t t ¼ 0. The concentration in the sampler can be evaluated from the mass balance (V s C s ¼ V w [C w0 – C w ]) C s ¼ C w0 K sw 1 À exp À 1 þ K sw V s V w R s t K sw V s 1 þ K sw V s V w (7.39) which reduces to Eq. (7.12) in the limit V w -N. With Eqs. (7.38) and (7.39) it is assumed that there are no c ompeting sorption phases (e quip- ment and pa rticula te/d issolve d or ganic mat ter ) in t he e xposu re sys tem. I n the short time limit, Eq. ( 7.38) ma y b e a pproximate d b y C w ¼ C w0 1 À R s t V w þÁÁÁ (7.40) K. Booij , B. Vrana and J.N. Huckins 158 Chapter 8 Tool for monitoring hydrophilic contaminants in water: polar organic chemical integrative sampler (POCIS) $ David A. Alvarez, James N. Huckins, Jimmie D. Petty, Tammy Jones-Lepp, Frank Stuer-Lauridsen, Dominic T. Getting, Jon P. Goddard and Anthony Gravell 8.1 INTRODUCTION Global emissions of persistent bioconcentratable organic chemicals have resulted in a wide range of adverse ecological effects. Conse- quently, industry developed less persistent, more water soluble polar or hydrophilic organic compounds (HpOCs), which generally have low bioconcentration factors. However, evidence is growing that the large fluxes of these seemingly more environmentally friendly compounds (e.g., pesticides, prescription and non-prescription drugs, personal care and common consumer products, industrial and domestic-use chemicals, and their degradation products) into aquatic systems on a world-wide basis may be responsible for incidents of acute toxicity and sublethal chronic abnormalities [1–3]. These adverse effects include altered behavior, neurotoxicity, and severely impaired reproduction [4]. Furthermore, the presence of these HpOCs likely plays a major role in the endocrine disrupting effects of complex mixtures of chemicals present in aquatic environments [5,6]. In regard to physiological effects, pharmaceuticals are of particular concern because they are designed to elicit diverse pharmacological responses. Unfortunately, $ Although the research described in this chapter has been funded in part by the United States Environmental Protection Agency through (IAG #DW14900401) to USGS-CERC, it has not been subjected to Agency review and, therefore, does not necessarily reflect the views of the Agency and no official endorsement should be inferred. Comprehensive Analytical Chemistry 48 R. Greenwood, G. Mills and B. Vrana (Editors) Volume 48 ISSN: 0166-526X DOI: 10.1016/S0166-526X(06)48008-9 r 2007 Elsevier B.V. All rights reserved. 171 TABLE 8.1 Classes or specific chemicals known to concentrate in POCIS 23 pharmaceuticals including Acetaminophen Azithromycin Carbamazepine Propranolol Sulfa drugs (antibiotics) Tetracycline antibiotics 2 illicit drugs (methamphetamine, MDMA) Several natural and synthetic hormones 17b-Estradiol 17a-Ethynylestrad iol Estrone Estriol 12 Triazine herbicides including Atrazine Cyanazine Hydroxyatrazine Terbuthylazine Various polar pesticides including Alachlor Chlorpyrifos Diazinon Dichlorvos Diuron Isoproturon Metolachlor Various household and industrial products and degradation products including Alkyl phenols (nonylphenol) Benzophenone Caffeine DEET Indole Triclosan Urobilin (fecal contamination marker) Essentially, any compound with log K ow r3.0 Polar organic chemical integrative sampler (POCIS) 177 TABLE 8.5 Pharmaceutical compounds in the effluent of British WWTPs Chemical Matrix % recovery Site 1 a Site 2 Site 3 Survey 2 Survey 3 Survey 1 Survey 2 Survey 3 Survey 1 Survey 2 Survey 3 Acetaminophen 98 (2.5) b o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 Dextropropoxyphene 90 (2.3) 0.50 (6.9) 0.59 (22) 0.47 (26) 0.32 (15) 0.32 (3.3) 0.72 (10) 0.62 (12) 0.89 (9.3) Diclofenac 95 (2.5) 0.48 (20) 0.41 (26) 2.0 (9.0) 0.82 (49) 1.8 (94) 2.9 (6.4) 1.9 (24) 0.61 (5.1) Erythromycin 130 (18) 0.15 c 0.15 c o0.005 c o0.005 c 0.033 c 0.10 c 0.064 c o0.005 c Ibuprofen 99 (5.3) o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 Mefenamic acid 97 (7.4) o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 Propranolol 95 (2.2) 0.36 (3.8) 0.41 (20) 0.68 (36) 0.62 (14) 0.74 (2.0) 1.1 (7.1) 1.0 (2.5) 1.3 (7.3) Sulfamethoxazole 95 (4.3) o0.015 o0.015 0.17 (13) 0.16 (61) 0.19 (17) o0.015 o0.015 o0.015 Tamoxifen 93 (0.8) o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 o0.005 Trimethoprim 95 (2.8) 0.28 (7.7) 0.06 (10) 0.05 (59) 0.08 (26) 0.11 (10) 1.0 (5.1) 0.75 (7.5) 0.80 (8.0) Recovery of targeted analytes from fortified matrix and concentrations in POCIS (pharmaceutical configuration) samples from each site are given. Results are presented at micrograms of chemical sequestered per POCIS. CVs are given in parenthesis (n ¼ 3). a Survey 1 POCIS from Site 1 were lost during deployment. b Acetaminophen recovery from the fortified POCIS matrix performed at n ¼ 2. c Only one replicate from each survey was analyzed. D.A. Alvarez et al. 190 Fig. 8.5. Selected LC–MS extracted ion chromatograms for trimethoprim, propranolol and dextropropoxyphene in a POCIS extract from Site 3, Survey 2 (Replicate B) of the pharmaceutical reconnaissance in British WWTP effluents. 191 Polar organic chemical integrative sampler (POCIS) . Analytical Chemistry 48 R. Greenwood, G. Mills and B. Vrana (Editors) Volume 48 ISSN: 0 166 -526X DOI: 10.10 16/ S0 166 -526X( 06) 48008-9 r 2007 Elsevier B.V. All rights reserved. 171 TABLE 8.1 Classes or specific. (2.3) 0.50 (6. 9) 0.59 (22) 0.47 ( 26) 0.32 (15) 0.32 (3.3) 0.72 (10) 0 .62 (12) 0.89 (9.3) Diclofenac 95 (2.5) 0.48 (20) 0.41 ( 26) 2.0 (9.0) 0.82 (49) 1.8 (94) 2.9 (6. 4) 1.9 (24) 0 .61 (5.1) Erythromycin. o0.005 Propranolol 95 (2.2) 0. 36 (3.8) 0.41 (20) 0 .68 ( 36) 0 .62 (14) 0.74 (2.0) 1.1 (7.1) 1.0 (2.5) 1.3 (7.3) Sulfamethoxazole 95 (4.3) o0.015 o0.015 0.17 (13) 0. 16 (61 ) 0.19 (17) o0.015 o0.015