Humic Acid-Bound Polycyclic Aromatic Hydrocarbons (PAHs) in Rhizosphere of Rice (Oryza sativa L.)

The presence of humic acid (HA) makes it extremely difficult to determine and quantify accurately polycyclic aromatic hydrocarbons (PAHs) in aquatic environment because of their complex and strong interaction. To solve this problem, a new method was developed in this work through the combination of PARAFAC and fluorescence spectroscopy, which mainly includes: (1) the fluorescence quantum yield acquisition of PAHs with and without HA by PARAFAC; (2) the concentration score correction of PAHs in validation and test sets using the fluorescence quantum yields; and (3) the prediction of PAHs concentration in the validation and test sets in the presence of HA by corrected concentration. Using this method, the PAHs concentration on the level of µg L−1 in the test samples with HA of 2.5 mg/L and 5.0 mg/L can be successfully predicted with the root mean square error below 0.15 µg L−1, relative error of prediction below 4% for validation samples, recoveries of each PAH between 82.5% and 102.6% for test samples.

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Polycyclic Aromatic Hydrocarbons in Different Varieties of Rice (Oryza sativa) from Yobe State, Nigeria

Environment and Pollution ◽

10.5539/ep.v7n2p21 ◽

2018 ◽

Vol 7 (2) ◽

pp. 21 ◽

Cited By ~ 1

Author(s):

Joseph Clement Akan ◽

Joshua Yohanna Dawa ◽

Lawan Inuwa Bukar ◽

Zakari Muhammed

Keyword(s):

Oryza Sativa ◽

Polycyclic Aromatic Hydrocarbons ◽

Cancer Risk ◽

Aromatic Hydrocarbons ◽

Hazard Index ◽

Human Consumption ◽

Average Daily Dose ◽

Daily Dose ◽

Polycyclic Aromatic ◽

Rice Samples

The present study determined the levels of sixteen polycyclic aromatic hydrocarbons (PAHs) in rice (Oryza Sativa) samples from six agricultural locations in Bade and Karasuwa Local Government Areas, Yobe State, Nigeria. Four varieties of rice (FARO 42, 44, 45 and 52) were collected for this study. The concentrations of PAHs in the study rice samples were lower than the maximum allowable concentration (MAC), average daily dose (ADD) of PAHs in the different variety of rice from the six agricultural locations shows that FARO 44 had the highest ADD (5.84 x1011 mg/kg), while FARO 52 shows the lowest ADD (1.20 x1015 mg/kg). The potential for non-carcinogenic PAHs in this study revealed that FARO 42 has the highest hazard index (2.04 x1011 mg/kg). Result from incremental lifetime expectancy cancer risk shows that FARO 44 from Jawa had the highest value (4.19 x1010 mg/kg), while the lowest value (7.61 x1015 mg/kg) was recorded for FARO 52 from Rina Kuna agricultural location. Results from the present study shows that the rice samples from the study locations are safe for human consumption and not significantly contaminated by PAHs.

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Micro-Solid Phase Extraction of Polycyclic Aromatic Hydrocarbons in Water using either C18 or Molecularly Imprinted Polymer Membranes: Analytical Merits and Limitations

Sains Malaysiana ◽

10.17576/jsm-2021-5001-13 ◽

2021 ◽

Vol 50 (1) ◽

pp. 123-133

Author(s):

Siti Nurul Umira Mohd Sabari ◽

Saw Hong Loh ◽

Sazlinda Kamaruzaman ◽

Noorfatimah Yahaya ◽

Wan Mohd Afiq Wan Mohd Khalik

Keyword(s):

Polycyclic Aromatic Hydrocarbons ◽

Humic Acid ◽

Aromatic Hydrocarbons ◽

Solid Phase ◽

Environmental Water ◽

Phase Extraction ◽

Imprinted Polymer ◽

Molecularly Imprinted ◽

Polycyclic Aromatic ◽

Pre Treatment

Sample pre-treatment is often the bottleneck in an analytical process. Due to the drawbacks of conventional sample pre-treatment methods, microextraction utilizing lower amounts of adsorbents and organic solvents are therefore favoured. A micro-solid phase extraction (μ-SPE) technique coupled with gas chromatography-flame ionization detection (GC-FID) was successfully developed for the analysis of selected polycyclic aromatic hydrocarbons (PA Hs), namely phenanthrene, fluoranthene, and pyrene, in environmental water. In this study, μ-SPE techniques using C18 and molecularly imprinted polymer (MIP) membranes were optimized, validated, and applied to the analysis of selected PA Hs in environmental water samples. The analytical merits were compared, and the two methods were evaluated in terms of linearity, repeatability, and relative recovery. Under the optimal extraction conditions, both μ-SPE techniques using either C18 or MIP membranes as the adsorbents offered comparable ultratrace analysis of the selected PA Hs in the range of 0.003 to 0.01 μg L–1. The extraction strength of C18 membranes was superior to that of MIP membranes for the extraction of low molecular weights PA Hs from water in the presence of humic acid as a matrix factor. The C18membranes overcome the non-covalence interaction between PA Hs and humic acid and thus achieve better recovery.

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