Coupling of molecular imprinted polymer nanoparticles by high performance liquid chromatography as an efficient technique for sensitive and selective trace determination of 4-chloro-2-methylphenoxy acetic acid in complex matrices

4-chloro-2-methylphenoxy acetic acid [MCPA] is one of the most important pesticides which is extensively used to control weeds in arable farmland. Exposure to this compound occurs in general population and persons who occupationally handle it. The aim of this present work was the preparation of MCPA imprinting polymer and its application as a selective sample preparation technique for trace determination of MCPA in biological and environmental samples. In this study, MCPA imprinting polymer was obtained by precipitation polymerization using methacrylic acid [the functional monomer], ethylene glycol dimethacrylate [the cross-linker], 2,2'-azobisisobutyronitrile [the initiator] and MCPA [the template molecule] in acetonitrile solution. The MIP-NPs were characterized by thermogravimetric analysis and scanning electron microscopy. The optimization process was carried out applying batch method. After optimization of the parameters, affecting the adsorption and desorption of analyte, urine and different water samples were used to determine MCPA. Imprinted MCPA molecules were removed from the polymeric structure using acetic acid in methanol [20:80 v/v%] as the eluting solvent. Both sorption and desorption process occur within 10 min. The maximum sorbent capacity of the molecular imprinted polymer is 87.4 mg g-1. The relative standard deviation and limit of detection for water samples by introduced selective solid phase extraction were 4.8% and 0.9 micro g L-1, and these data for urine samples were 4.5% and 1.60 micro g L-1, respectively. The developed method was successfully applied to determine MCPA in urine and different water samples

Evaluation of occupational exposure of glazers of a ceramic industry to cobalt blue dye

Cobalt is one of the most important constituent present in ceramic industries. Glazers are the relevant workers when they are producing blue colored ceramic, causing occupational exposure to such metal. Through this study, urinary cobalt was determined in glazers in a ceramic industry when they were producing blue-colored ceramic glazes. In this case-control study, spot urine samples were collected from 49 glazers at the start and end of work shifts [totally 98 samples] in 2011. Control group were well matched for age, height, and weight. A solid phase extraction system was used for separation and preconcentration of samples followed by analysis by inductively coupled plasma-atomic emission spectroscopy [ICP-AES]. All participants filled out a self administered questionnaire comprises questions about duration of exposure, work shift, use of mask, skin dermatitis, kind of job, ventilation system, overtime work, age, weight, and height. The lung function tests were performed on each control and cobalt exposed subjects. Analysis of covariance [ANCOVA] was used to evaluate the obtained results. Urinary levels of cobalt were significantly higher in the glazers compared to the control group. There were significant differences at urinary concentration of cobalt at the start and end of the work shift in glazers. Spirometric parameters were significantly lower in the glazers compared to the control group. Among the variables used in questionnaire the significant variables were dermatitis skin, mask, ventilation, and overtime work. This study verified existence of cobalt in the urine glazers showing lower amount than the ACGIH standard

Synthesis of molecularly imprinted polymer as a solid phase sorbent for pesticide dursban

This study describes the synthesis of molecularly imprinted polymers [MIPs] by using an Anti-ChE OPs, namely dursban, as a template. Non-covalent bulk polymerization was successfully applied to synthesis different imprinted and non-imprinted polymers with MAA, MMA, AA, and 4-vpy as monomer in selected porogens [chloroform, toluene, and acetonitrile]. In order to evaluate the template binding of the polymers, equilibrium binding experiments was carried out. High binding amount of imprinted polymers compared to non-imprinted polymer was due to effective imprinting or encoding of dursban template shape in the polymer matrixes. From this study, the dursban imprinted polymers prepared using acidic MAA as a functional monomer showed excellent molecular binding ability for dursban. This is because the hydrogen binding interaction between dursban and MAA may be formed between sulfur, oxygen, chlorine, and nitrogen groups of dursban and carboxyl group of MAA. The results shows the use of chloroform as porogen, with a poor hydrogen binding power, significantly affects the binding extend of the MIPs. MAA and chloroform were found to be the most suitable monomer and porogen for the preparation of appropriate dursban molecularly imprinted polymers. This study has shown the possibility of synthesizing and using molecularly imprinted polymers as sorbent for an Anti-ChE Ops