Development of HPLC Determination Method for Trace Levels of 1-, 2-Nitropyrenes and 2-Nitrofluoranthene in Airborne Particulates and Its Application to Samples Collected at Noto Peninsula

Abstract

1-Nitropyrene (1-NP), 2-NP and 2-nitrofluoranthene (2-NFR) are useful markers for studying the atmospheric behaviors of polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs). However, present methods for measuring trace levels of these compounds are lesssensitive and laborious. Here we describe several improvements to a previously reported high-performance liquid chromatography-chemiluminescence detection system that allows it to determine trace levels of 1-, 2-NPs and 2-NFR. The proposed system was equipped with a reducer column packed with Pt/Rh instead of zinc whose lifetime was limited. The combination of Cosmosil MS-II (monomeric ODS) and AR-II (polymeric ODS) columns was used instead of polymeric ODS columns as the separator column to improve the separation. An ethanol mixture with acetate buffer (pH 5.5) was used in place of an acetonitrile mixture with the same buffer to activate the reducer column. The same ethanol mixture was used as the mobile phase for the clean-up column. The switching time of the column switching valve was optimized to concentrate the amino-derivatives of above NPAHs quantitatively on the concentrator column. The concentrations of bis(2,4,6-trichlorophenly) oxalate and hydrogen peroxide in the chemiluminescence reagent solution were optimized to 0.4 mM and 30 mM, respectively, to increase the sensitivity. Under the above conditions, the detection limits (S/N = =3) of 1-, 2-NPs and 2-NFR were 1 fmol (0.25 pg), 10 fmol (2.5 pg) and 4 fmol (1 pg), respectively. The proposed system was effectively used to determine trace levels of 1-, 2-NPs and 2-NFR in airborne particulates collected at Noto Peninsula. The atmospheric concentrations of 1-, 2-NPs and 2-NFR were not more than sub pg m-3 levels. They were higher in winter (January) than in summer (July). In both seasons, the concentrations were in decreasing order, [2-NFR]¤[1-NP]¤[2-NP].

Atmospheric Polycyclic and Nitropolycyclic Aromatic Hydrocarbons in an Iron-manufacturing City

“…Other conditions were the same as in our previous reports (Hayakawa et al, 1995;Hayakawa et al, 1991). PAHs and NPAHs were determined using HPLC with fluorescence and chemiluminescence detectors, respectively, according to our reports (Pham et al, 2013;Hayakawa et al, 2011Hayakawa et al, , 2001Tang et al, 2005).…”

Recent analytical methods for atmospheric polycyclic aromatic hydrocarbons and their derivatives

“…The analytical methods available for NPAHs in airborne particulates were limited to several chromatographic methods such as GC and HPLC as described in our previous report (Hayakawa, ). Among them, GC–MS with negative ion chemical ionization (GC/NICI‐MS) (Alves et al, ; Kawanaka et al, ; Ringuet, Albinet, Leoz‐Garziandia, Budzinski, & Villenave, ), GC–MS (Tutino et al, ) and HPLC‐chemiluminescence detection (HPLC‐CLD) (Hayakawa, Kitamura, Butoh, Imaizumi, & Miyazaki, ; Hayakawa, Noji, Tang, Toriba, & Kizu, ; Hayakawa et al, ; Tang et al, , ; Tang, Toriba, Kizu, & Hayakawa, ) (Figure ) were mostly used. By using the HPLC‐CLD method, we identified the environmental behaviors such as levels, compositions and main sources of NPAHs in cities located in the East Asian area (Tang, et al, ; Hayakawa et al, ).…”