Investigating polycyclic aromatic hydrocarbons profiles in higher plants using statistical models.

Thirty-six higher plants sampled from Olomoro, Irri, Uzere, and Oginni exploration sites in the Niger Delta region of Nigeria were subjected to GC/MS analysis to assess the occurrence, distribution and profiles of polycyclic aromatic hydrocarbons (PAHs) contained in them. The sigma28PAHs ranged from 335 to 3094 ng/g. The results of the nonparametric regression models showed that PAHs concentration in a plant cannot be used in isolation to deduce the total PAHs concentration in soils hosting the plant since PAHs concentration in a plant is influenced by the presence (or absence) of other plants in that location. A combination of Factor analysis (FA) and principal component analysis (PCA) were used to recognize PAHs concentration patterns among the plants in the studied locations and individual PAHs compounds. Woody annuals and perennial plants formed similar patterns in Oginni and Irri locations. Three main clusters were formed by all the compounds with naphthalene and 2-methylnaphthalene standing as outliers in all the four locations.

Assessment of organochlorine pesticides residues in higher plants from oil exploration areas of Niger Delta, Nigeria.

The concentrations and distributions of organochlorine pesticides (OCPs) in some higher plant samples collected from oil exploration areas of the Niger Delta, Nigeria were examined. The concentrations of Σ(25)OCP ranged from 82 to 424, 44 to 200 , 34 to 358, 33 to 106 and 16 to 75 ng/g in Olomoro, Oginni, Uzere, Irri and Calabar plants, respectively. The compositional profiles of the analysed OCPs in most of the plants showed no fresh inputs in the area. The OCPs detected in the samples could have resulted from pesticide usage for intense farming activities cum the use of pesticides to control household pests and insects in the area. Drilling fluids and corrosion inhibitors used in petroleum explorations also have chlorinated compounds as additives thereby serving as potential sources of OCPs. Among the studied plants, elephant grass showed high bioaccumulation and phytoremediation potentials of OCPs. The ΣHCH concentrations exceeded the allowable daily intake limit thereby serving as potential threat to humans.

Simultaneous determination of caffeic acid phenethyl ester and its metabolite caffeic acid in dog plasma using liquid chromatography tandem mass spectrometry.

A simple, reliable and sensitive method for the simultaneous determination of caffeic acid phenethyl ester (CAPE) and its metabolite caffeic acid (CA) in dog plasma was developed using liquid chromatography tandem mass spectrometry (LC-MS/MS). The sample pretreatment generally involved protein precipitation treatment (PPT) and direct dilution. CAPE and CA were separated with a C18 reversed-phase column. Electrospray ionization (ESI) interface operated in negative mode was chosen for ionization. Multiple reaction monitoring (MRM) mode was selected for data acquisition. The quantification range was 10.0-10,000.0 ng mL(-1). The intra- and inter-batch accuracies were within 92.5-107.0% with relative standard deviation (RSD, %) no more than 10.5%. CAPE and CA were proved to be stable in stabilizer-treated dog blood and PPT-treated plasma during the sampling and pretreatment period. The applicability has been evaluated with real samples from treated dogs.

Biomonitoring potentials of polycyclic aromatic hydrocarbons (PAHs) by higher plants from an oil exploration site, Nigeria.

Higher plants sampled from a moderately polluted exploration site were analyzed with gas chromatography-mass spectrometry to determine the occurrence and sources of polycyclic aromatic hydrocarbons (PAHs). The concentrations of the sum of 28 target PAHs (designated as Σ(28)PAH) in the leaves of higher plant samples ranged from 365 to 2870 µg/kg with an average of 1430 µg/kg. The majority of the target compounds were detected except 9,10-diphenyl anthracene and dibenzo(a,h)anthracene, which were below the detection limits in most plant samples. In addition, the concentrations of the 2- and 3-ring PAHs, especially naphthalene and its alkylated derivatives, were generally higher than the 4-, 5- and 6-ring PAHs. Based on the results obtained in the present study, higher plants, especially non-woody annual and perennial plants could serve as good phytoremediators for a PAHs polluted sites.