Solid-Liquid Extraction Room Temperature Phosphorimetry and Pattern Recognition for Screening Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls in Water Samples ANDREA F. ARRUDA, † HECTOR C. GOICOECHEA, ‡ MARINA SANTOS, † ANDRES D. CAMPIGLIA,* ,† AND ALEJANDRO C. OLIVIERI* ,§ Department of Chemistry, North Dakota State University, Fargo, North Dakota 58105-5516, and Departamento de Quimica Analitica, Facultad de Ciencias Bioquim icas y Farm aceuticas, Universidad Nacional de Rosario, Suipacha 531, (S2002LRK) Rosario, Argentina Solid-liquid extraction room temperature phosphorimetry and pattern recognition are being proposed for screening polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) in water samples. Both classes of pollutants are extracted with the same membrane using a syringe kit, and their phosphorescence spectra are recorded directly from the surface of the solid support. The entire experimental procedure takes less than 8 min per sample, and the limit of detection for 10 mL of water is at the parts-per-billion level. On the basis of the sample spectrum, pattern recognition is used to classify positive water samples as containing PAH,PCB,or both.The feasibility of this approach and its ability to avoid unnecessary chromatographic analysis of uncontaminated samples is demonstrated with several complex mixtures and the analysis of heavily contaminated “ real world” samples. The recognition ability was 100%, while the prediction ability was close to perfect. Introduction Polycyclicaromatichydrocarbons(PAH)and polychlorinated biphenyls (PCB) are ubiquitous in the global environment, and their routine monitoring is recommended to avoid human health threat.Exposure to manyPAH and PCBbearing meta and para substitution has been associated to carci- nomas, reproductive toxicity, and other developmental defects. Routine monitoring of these pollutants in public water supplies is typically done through sample precon- centration and chromatographic analysis (1). Preconcen- tration is achieved by either liquid -liquid extraction (LLE) or solid -liquid extraction (SLE). PAH analysis is based on two chromatographic techniques. High-performance liquid chromatography (HPLC) with coupled ultraviolet (UV) and fluorescence detection is used for initial screening and quantitative determination in samples of relatively simple matrix complexity. For heavily contaminated waters, gas chromatography-mass spectrometry (GC-MS) is used as a supportingtechnique.Similarly,PCBanalysisrequiresusing more than one chromatographic technique. HPLC with UV detection is used for screening purposes, separating the 209 congeners in several fractions. Gas chromatography with electron capture (GC-ECD) and mass spectrometric (GC- MS) detection are then employed to analyze the HPLC fractions (1). Although chromatographictechniquesare well-suited for monitoring PAH and PCB, it would be advantageous to the environmentalchemist havinga single monitoringapproach to know beforehand if a sample needs the complete chromatographicprocedure.The main reason fordeveloping such an approach is to avoid unnecessary chromatographic analysis of uncontaminated samples. To the extent of our literature search, the approach does not exist for the simultaneous screening of PAH and PCB. To fulfill this gap, we are proposing SLE-room temperature phosphorimetry (RTP) and pattern recognition. Initial research on SLE-RTP of PAH and PCB optimized experimental parameters for enhancing their phosphores- cence on extraction membranes (2-4). SLE was performed with a vacuum pump using the classical procedure of processing 1 L of water through a 38 mm active diameter disk. The extraction membrane was then cut into six pieces to fit in the substrate holder for RTP measurements, spotted with 5 μL of phosphorescence enhancer (0.1 M TlNO3) and dried in an oven for 15 min at 110 °C. Although the limits ofdetection (LOD) were excellent (parts per billion, ppb) for RTP analysis, the SLE procedure was still inconvenient for screeningpurposes because ofthe bulkyglassware,vacuum pump, oven-drying step, and relatively long analysis time (approximately 45 min). A new SLE method was then developed for RTP analysis of PAH that used a syringe kit to extract 10 mLofwater through a 13 mm disk (5). The syringe method, which takes less than 5 min per sample, was then applied to the analysis ofpolychlorinated dibenzofurans (6). In both cases,the SLE-RTP analyticalfigures ofmerit assured accurate pollutant quantitation at the ppb levels. In the present work, we use the syringe method to determine the presence of PAH, PCB, or both within the same water sample. The screening capability of SLE-RTP is enhanced using linear discrimination analysis (LDA), a well- known chemometric method (7). The analytical merits of this approach include simple and rapid experimental pro- cedure,lowlevelsofdetection,and pollutant classselectivity without major separation steps. The methodology is suited for portable instrumentation and field analysis,and because of its nondestructive nature, it can be interfaced with high- resolution techniques for subsequent specific compound identification. Its ability to avoid unnecessary chromato- graphicanalysisofuncontaminated samplesisdemonstrated with several complex mixtures and the analysis of heavily contaminated “real world” water samples. Experimental Section Chemicals. All chemicals were analytical-reagent grade and used without further purification.Nanopure water (Ultrapure Water System, Barnstead, MA) was used throughout. SPEC *Correspondingauthor (A.D.C.)phone: (701)231-8702;fax: (701)- 231-8831; e-mail: Andres.Campiglia@ndsu.nodak.edu. (A.C.O.) phone/ fax: 54-341-4372704; e-mail: aolivier@fbioy.unr.edu.ar. † North Dakota State University. ‡ On leave from Catedra de Quimica Analı ´tica I, Facultad de Bioquı ´mica y Ciencias Biolo ´gicas, Universidad Nacional del Litoral, Santa Fe, Argentina. § Universidad Nacional de Rosario. Environ. Sci. Technol. 2003, 37, 1385-1391 10.1021/es020717h CCC: $25.00  2003 American Chemical Society VOL. 37, NO. 7, 2003 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 1385 Published on Web 03/01/2003