Journal of Chemical Health Risks
Volume:5 Issue: 2, Spring 2015

A study on polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) was conducted in a pooled sample of breast milk from 27 first-time mothers (primiparous) living in twelve locations at mesoregion industrial area, southern of Rio de Janeiro, Brazil, between August 2012 and July 2014. Questionnaires with questions regarding to food habits, social and economic conditions, places of dwelling were applied. Mothers were breast-feeding only one infant and milk was collected between 4 and 6 weeks after delivery. TEQs of PCDDs/Fs, and dl-PCBs were 10.6, 4.77, 6.96 TEQ pg/g, respectively. The understanding and identification of pollution sources may be helpful for taking better counter measures against breast milk dioxin contamination. It’s important for pregnant women to have a diet free as possible of contaminants chemical. Further research must be undertaken in the context of epidemiological investigations to more accurately assess the effects of these compounds.

In the current work, a new version of rank annihilation factor analysis was developedto circumvent the rank deficiency problem in multivariate data measurements.Simultaneous determination of dissociation constant and concentration of monoprotic acids was performed by applying model-based rank annihilation factor analysis on variation matrices of spectrophotometric acid-base titrations data. Variation matrices can be obtained by subtracting first row of data matrix from all rows of the main data matrix. This method uses variation matrices instead of multivariate spectrophotometric acid-base titrations matrices to circumvent the rank deficiency problem in the rank quantitation step. The applicability of this approach was evaluated by simulated data at first stage, then the binary mixtures of ascorbic and sorbic acids as model compounds were investigated by the proposed method. At the end, the proposed method was successfully applied for resolving the ascorbic and sorbic acid in an orange juice real sample. Therefore, unique results were achieved by applying rank annihilation factor analysis on variation matrix and using hard soft model combination advantage without any problem and difficulty in rank determination.

Many factors are involved in learning and memory processes including brain nuclei, neurotransmitter systems, and the activity of ion channels. Studies showed inconsistent effects of calcium channel blockers on learning process, especially memory consolidation; however, little is known about their effect on memory acquisition and retrieval. Accordingly, the present study aimed to determine the effects of verapamil calcium channel antagonist as a representative of the phenylalkylamine group on different stages of memory and learning processes including acquisition, consolidation and retrieval in mice. In this experimental study, 150 male albino mice with a mean weight of 30 g were used. The mice were trained in a passive avoidance-learning task (1 mA shock for 2 seconds for evaluation of memory acquisition and consolidation and 3 seconds for evaluation of memory retrieval). The effect of verapamil (1, 2.5, 5, 10, and 20 mg/kg) on memory consolidation and the most effective dose of consolidation phase on memory acquisition and retrieval was assessed. For the evaluation of memory consolidation, the animals received the drug intraperitoneally immediately after training, while for evaluation of memory acquisition and retrieval, the drug was injected one hour before training. Memory retrieval test was performed 48 hours after training (the length of time it took the animal to enter the dark part of the device). The results showed that verapamil injection exerted no effect on memory acquisition and consolidation; nevertheless, it was capable to disrupt memory retrieval in 10 and 20 mg doses. These results indicate that as a phenylalkylamine calcium channel antagonist, high doses of verapamil can impair memory.

A simple, sensitive and selective method for extraction of trace amounts of Pb (II) in water samples based on the adsorption of its modification nano polyacrylonitrile fiber (PANF) was examined in this study. PANF was prepared by adding acrylic fibers to ethylendiamin (EDA) with different concentration solutions. A new technique using a solid phase extraction (SPE) cartridge with modified PANF as sorbent was developed for the preconcentration of trace amounts of lead and was determined by flame atomic absorption spectrometry (FAAS). Ethylenediamine plays a key role as chelating reagent on ultrahigh specific surface of PANF. Some of the important parameters on the preconcentration and complex formation were selected and optimized. Under the optimized conditions the limit of detection (LOD) and limit of quantification (LOQ) were 0.167, 0.562 and the proposed method has a good reproducibility 0.81% (RSD %). The enrichment factor was 200 and the percentage of recovery was in the range of 95-100%. The method was successfully applied to the recovery of Pb2+in different type of water samples. PANF and its derivate such as PANF-EDA in this study are full of potential to use as an excellent adsorbent in the extraction method like SPE and solid phase micro extraction (SPME).

A simple and efficient directly suspended droplet micro extraction in conjunction with gas chromatography-electron capture detector (GC-ECD) has been developed for extraction and determination of organochlorine pesticides (OCPs) from water samples. In this technique a micro drop of 1-dodecanol is delivered to the surface of an aqueous sample while being agitated by a stirring bar in the bulk of solution. Factors relevant to the extraction efficiency were studied and optimized. The optimized extraction conditions were extraction solvent: 1-dodecanol; extraction temperature: 60◦C; NaCl concentration: 0.5M; solvent extraction volume: 10 µL; stirring rate: 800rpm and the extraction time: 20 min. The detection limits of the method were in the range of 0.066–1.85 ngL−1, relation standard deviation (n=5) range were 0.102 - 0.964. A good linearity (r 2 ≥0.995) and a relatively broad dynamic linear range (25–2600ng.L−1) were obtained and recoveries of method were in the range of 90.729% - 102.343%. Finally, the proposedmethod was successfully utilized for pre concentration and determination of OCPs in different real samples.We successfully developed a method based on the DSDME technique combined with capillary GC-ECD for the analysis of OCPs in the water samples and compared with the conventional sample preparation method such as LPME.

In this study, the essential oil obtained by hydrodistillation of the aerial parts of Sclerorhachis platyrachis (Boiss.) Podlech ex Rech. f. (Compositae), growing wild in Sabzevar, Khorasan Razavi Province (Iran), was analyzed by GC and GC/MS. The total yield of volatiles was 0.38% (w/w). Sixty- three compounds representing 89.2% of the aerial parts oil were identified. The main components of the oil were β-pinene (17.5%) and γ-terpinene (15.4%). The oil was rich in monoterpenoids, and among them, monoterpene hydrocarbons (48.7%) predominated over oxygenated monoterpenes (11.8%). The total flavonoid content of different extracts of the plant was in the range 52.4-172.3 mg/g, with the maximum amount being in the methanol extract. The antioxidant activities of the extracts were also measured based on radical scavenging activity of antioxidants using the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) method. The results showed that IC50 values of extracts of S. platyrachis are higher than for the standard synthetic antioxidants, BHT, ascorbic acid and gallic acid.

Several fruit trees including some cultivars of citrus tend to develop irregular bearing. Fruit thinning has been used for hundreds of years to manipulate blooming and crop load to improve the alternate bearing process. Frequently, combination sprays of two or more chemical thinners are used in various fruit trees and the thinning responses were additive and more effective than individual compounds. In this study, we investigated the effects of Naphthalene acetic acid and carbaryl alone and in combination in thinning of ‘Kinnow’ mandarin (Citrus reticulata Blanco) trees. Some characteristics such as fruit weight, diameter and volume, total soluble solid (TSS), titrable acidity (TA), TSS/TA, vitamin C and peel thickness were measured prior to harvest for 2010 and 2011 as a complete randomized block design with 13 treatments and four replications. Results showed that the application of NAA and carbaryl alone in June drop stage of fruit growth increased fruit thinning percentage, TSS of fruit juice, fruit weight, volume, diameter and length. These chemical thinners improved fruit size significantly by increasing the leaf/fruit ratio. Combination sprays could not effectively thin fruits than individual chemicals and thus had no effect on fruit size. Fruit characteristics such as TA, ascorbic acid, TSS/TA ratio and peel thickness were not affected by our treatments.

A sensitive and simple method based on the fluorescence quenching CdS quantum dots (QDs) was reported for the determination of copper(Cu2+) and nickel (Ni2+) in water samples. Water-soluble and biocompatible thioglycolic acid- capped CdSQDs was synthesized by one step process, then characterized by fluorescence, absorption spectroscopy and transmission electron microscopy (TEM). The fluorescence intensity of synthesized QDsremarkably decreased in the presence of Cu2+ and Ni2+ ions. The emission of CdSQDs had a linear decreasing relationship with Cu2+ and Ni2+ concentration in the range of 0.6 to 200 and 1 to 250 ng mL-1 with detection limits of 0.15 and 0.4 ng mL-1, respectively. Other potentially interfering ions such as iron, sodium, potassium, calcium, and magnesium ions did not affect the luminescence. The method showed good sensitivity and was satisfactorily applied to the determination of Cu2+ and Ni2+ contamination in real water samples, obtained from Nahand dam, Karkaj and Azarshahr well, tab and mineral waters.