Determination of Diamino- and Aminopyrenes by High Performance Liquid Chromatography with Chemiluminescence Detection

Abstract

A high performance liquid chromatographic (HPLC) method with chemiluminescence (CL) detection was developed for the sensitive determination of 1,3-diaminopyrene (1,3-DAP), 1,6-DAP, 1,8-DAP and 1-aminopyrene (1-AP). The HPLC conditions were as follows: column, Cosmosil 5C18 (4.6 mm i.d.X250 mm); mobile phase, 10 mM imidazoleperchloric acid buffer(pH 7.6)-acetonitrile (1:1, v/v); CL reagent, 0.02 mM bis(2,4,6-trichlorophenyl)oxalate (TCPO) and 15 mM hydrogen peroxide in acetonitrile. The oxidative degradation of DAPS and AP in the presence of metals was prevented by adding ascorbic acid to sample solutions. The calibration curves were straight over 2 orders of magnitude for all analytes, and their detection limits (as S/ N was 3) were in the sub-fmol range. Dinitro-and nitropyrenes in sooty emissions of diesel-and gasoline-engine cars could be determined by this HPLC after reductive conversion into DAPs and AP, respectively, by refluxing the samples in the presence of sodium hydrosulfide. Nitrated polycyclic aromatic hydrocarbons (NPAHs) have attracted much attention because of their potent mutagenic activity.' They are formed as undesirable by-products when various organic materials react with atmospheric nitrogen during combustion2,3 and are found in many environmental samples.4-6 Dinitropyrenes (DNPs) are the most mutagenic and carcinogenic of these NPAHs.'_9 Both gas chromatography (GC)10 and GC/ mass spectrometry6 have been reported as sensitive determination methods for DNPs. However, tedious procedures are required for cleaning and concentrating samples. On the other hand, a high performance liquid chromatographic (HPLC) method with fluorescence (FL) detection has also been reported' 1, with which DNPs were determined after a reductive conversion of DNPs into diaminopyrenes (DAPs). Although the FL detection was so selective that cleaning procedures became simpler, the sensitivity was not sufficiently high to detect them at trace levels in the environment.Recently, peroxyoxalate-chemiluminescence (P0-CL) detection has been developed as a highly sensitive and selective detection method for HPLC.'2,13 In our preliminary experiment, PO-CL detection was much more sensitive for DAPs and 1-AP than was FL detection. The observed peak heights, however, were significantly smaller than those from the extrapolated calibration curves when the injection amounts were less than pmol. This phenomenon disturbed the trace analysis. We found that DAPs and 1-AP were very unstable in the presence of metals and that this reaction was the main reason for the above phenomenon. The problem was solved by adding an antioxidant, such as ascorbic acid (AA), enabling the DAPs and 1-AP to be determined at trace levels. The purpose of this report is to propose an HPLC method with PO-CL detection for 1,3-, 1,6-, 1,8-DAPs and 1-AP whose sensitivities are much higher than those with FL detection. ExperimentalChemicals and solutions 1,3-, 1,6-and 1,8-DAPs and 1-AP were prepared according to a report by Hashimoto et a1.14 All other chemicals we...

Determination of Atmospheric Nitrobenzanthrones by High-Performance Liquid Chromatography with Chemiluminescence Detection

“…16,29,30,32 Recently, a combination of hydrazine and Raney nickel catalyst was used to reduce 3-NBA. 26 In the experiment, NBA isomers were reduced by Pt/Rh catalyst.…”

Separation and Determination of Trace Dinitropyrenes by Means of Off-Line Reduction-HPLC-Chemihiminescence Detection. Application to Assessing Atmospheric Environment

“…Table 2 shows the detection limit of the present method, together with those of the conventional methods such as fluorescence9 and CL methods. 6 The present method thus improved substantially the sensitivity for the determination of DNP.…”

“…5. The use of ascorbic acid has been proposed for the improvement of CL stability by Hayakawa et al 6 System A showed a small CL intensity without any peak separation. Although System B has much improved the intensity and has achieved resolution of three peaks, a negative peak due to ascorbic acid was observed, resulting in distortion of the baseline.…”

Distribution and Source of Atmospheric Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons in Tieling City, Liaoning Province, a Typical Local City in Northeast China

“…The solution was filtered with a 0.45 μm HLC-Disk membrane filter (Kanto Chemical Co., Inc., Tokyo, Japan), and an aliquot of this solution was injected into the HPLC system for NPAHs. Other conditions were the same as in our previous reports (Tang et al, 2002a;Hayakawa et al, 1991).…”