RO129029A2 - Method for determining pahs in water using lc/ms/ms techniques, after previous solid-phase extraction () of samples - Google Patents

Abstract

The invention relates to a method for determining polycyclic aromatic hydrocarbons from water samples. According to the invention, the method comprises the solid-phase extraction of samples followed by the quick and selective analysis of the sample on a chromatographic column, at a temperature of 25...45°C, mobile phase gradient of HO/CHCN, a flow rate of 400...600 μ L/min, using an atmospheric pressure ionization source, at source and compound parameters corresponding to each of the assessed polycyclic aromatic hydrocarbon.

Description

The invention relates to an analytical method for the determination of polycyclic aromatic hydrocarbons (PAHs) in waters using LC / MS / MS (liquid chromatography coupled with mass spectrometry) technique after prior sample extraction using SPE solid phase extraction.

Abroad, the most common methods of investigating PAHs from environmental and food samples are: High Performance Liquid Chromatography (HPLC) with Fluorescence Detection (FLD) and Gas Chromatography Detected by Mass Spectrometry (CG / MS) [1-3]. Because HPLC-FLD is a difficult technique to use for PAHs that have low fluorescence transmission such as indeno [1,2,3-cd] pyrene [4] and CG / MS is a suitable technique for analyzing low polarity compounds [ 1] but it requires derivatization of compounds, in recent years it has been tried to replace these methods with LC / MS / MS technique using different sources for ionization of these compounds [1-4]. electrospray ionization (ESI) and chemical ionization at atmospheric pressure (APCI) although used for the vast majority of compounds were considered to be inadequate for PAHs [1, 2], atmospheric pressure photoionization (APPI) is a type new ionization source and is being tested for this application [1, 4]. For all these types of analytical tools, the extraction methods used are: liquid-liquid extraction and solid phase extraction (SPE).

In the country, the determination of polycyclic aromatic hydrocarbons (PAHs) from environmental and food samples is a topical issue [5-8]. However, according to our information, until now, no LC / MS / MS technique has been used as an analytical method for the determination of these compounds in water after previous sample extraction using solid phase extraction (SPE) technique.

The aim of the present invention is to develop an LC / MS / MS (liquid chromatography coupled with mass spectrometry) analytical method for determining PAHs in water using solid phase extraction (SPE).

The technical problems that the invention solves are: separation, identification, detection and quantification of the analytes that are performed simultaneously by LC / MS / MS, this allowing the confirmation of the presence of the analytes in samples by the presence of characteristic ions.

ICIA Director,

CS II Mircea Chintoanu (x - 2 O 1 2 - O O 3 3 2 - 1 4 -05- 2012

Description of the invention in the first MS concurrently with the presence of the specific fragments of the analytes studied in the second MS.

Advantages of the method: it is fast, economical and selective allowing the analysis of small volumes of sample;

The advantages of the extraction method: it is fast, selective and allows the removal of toxic solvents from the preparation stages of the sample for analysis.

The proposed method allows the determination of PAHs from water samples using as extraction method, solid phase extraction.

Figure 1 shows a chromatogram obtained for PAHs studied in water.

Solid phase extraction consists of the conditioning, loading, washing and eluting of the cartridges used with different small volumes V of CH2Cl2, H2O and CH3OH and finally reconstituted with a mobile volume V.

Chromatographic analysis of polycyclic aromatic hydrocarbons in water is performed by injecting a sample volume V through a dedicated chromatographic column with dimensions 5ym, 4.6 * 150 mm maintained at a temperature of

25 ... 45 ° C. The analytes were carried through the chromatographic column using a mobile phase gradient of H ₂ O / CH ₃ CN, v / v, with a flow rate of 400 ... 600 pL / min, where the percentage of H ₂ O varies between 0. ..20% in a time interval of 0..35 min. The sample reached the detector is ionized with an APCI (chemical ionization at atmospheric pressure) source. The source and compound parameters are determined to obtain the best area for each precursor-product ion pair characteristic of each PAH analyzed.

The performance parameters of the method for determining PAHs from water samples are:

- detection limits: 0.009-0.019 mg L ' ^{1 2} ;

- limits of quantification: between 0.027-0.057 mg-L ¹ ;

- degrees of recovery: between 59-97%.

1. Michael Smoker, Kevin Tran, Robert E. Smith, Determination of Polycyclic Aromatic Hydrocarbons (PAHs in Shrimp, J. Agric. Food Chem., 58 (23), 2010,12101-12104;

2. Hiroshi Moriwaki, Liquid Chromatography-Mass Spectrometry for the Analysis of Environmental Mutagens, Current Anal. Chem., 3, 2007, 69-79;

ICIA Director,

CS II Mircea Chintoanu ¢ (-2 0 1 2 - 0 0 3 3 2 -1 4 -05- 2012 (Description of the invention

3. Paolo Bruno, Maurizio Caselli, Gianluigi de Gennaro, Maria Tutino, Determination of polycyclic aromatic hydrocarbons (PAHs) in particulate matter collected with low volume samplers, Talanta, 72, 2007,1357-1361.

4. Hiroshi Moriwaki, Miho Ishitake, Shusaku Yoshikawa, Hidekazu Miyakoda, Jean-French Alary, Determination of polycyclic aromatic hydrocarbons in sediment by liquid chromatography-atmospheric pressure photoionization-mass spectrometry. Analytical sciences, 20 (2), 2004, 375-377.

5. Livia Alhafez, Nicoleta Muntean, Edward Muntean, Tania Mihăiescu, Radu Mihăiescu, Dumitru Ristoiu, Polycyclic aromatic hydrocarbons in wastewater sewerage system from the Cluj-Napoca area, Environ Eng. Mgmt. J., 11 (1), 2012, 5-12.

6. Simona Dobrinas, Gabriela Stanciu, Elisabeta Chirila, Alina Daria Soceanu, Elena Paunescu, Dan Tiberius Epure, Occurrence of PAHs and PCBs in Petrochemical Wastewater, Ovidius University Annals of Chemistry, 22 (1), 2011, 21-26.

7. Alina Daria Soceanu, Simona Dobrinas, Viorica Popescu, Gabriela Stanciu, Polycyclic aromatic hydrocarbons infruitJuices, Ovidius University Annals of Chemistry, 22 (2), 2011, 113-116.

8. Antoaneta Ene, Oleg Bogdevich, Alina Sion, Thomas Spanos, Determination of polycyclic aromatic hydrocarbons by gas chromatography-mass spectrometry in soils from Southeastem, Microchem. J., 100, 2012, 36-41.

Claims (1)

CLAIM The process for the determination of polycyclic aromatic hydrocarbons (PAHs) from water samples using LC / MS / MS (liquid chromatography coupled with mass spectrometry) technique after prior solid phase extraction (SPE) characterized in that it is based a simple extraction method followed by a rapid and selective analysis of PAHs without derivatization or further processing of the samples, method developed on a dedicated chromatographic column with dimensions 5pm, 4.6 * 150 mm, maintained at a temperature of 25 ... 45 ° C, mobile phase gradient of H2O / CH3CN, v / v, percentage of H ₂ O of 0 ... 20%, flow rate of 400 ... 600 pL / min, time interval of 0..35 min , using an APCI (chemical ionization at atmospheric pressure) ionization source with source and compound parameters optimized to obtain the best area of the precursor-product pair characteristic of each PAH analyzed.