The paper presents two methods for determination of phthalates in polymer materials. The methods compared were gas chromatography combined with the mass spectrometry (GC/MS) and gas chromatography with electron capture detector (GC/ECD). The GC/ECD technique was chosen for this comparison, because the ECD detector was one of few capable of detecting phthalates. In both cases the same procedure of sample preparation with ultrasonic extraction was applied. Overall recoveries were 76-100 % with relative of standard deviation (R.S.D.) values in the range 0.6-19 %. The values of limit of detection (LOD) for GC/MS method ranged from 3.46 µg mL -1 to 10.10 µg mL -1 , depending on the determined phthalate, while in case of the GC/ECD method they were in the range from 2.97 µg mL -1 to 4.29 µg mL -1 . The methods were applied for determination of: dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, diisononyl phthalate, diisoocyl phthalate in polymer material. The seventeen kinds of samples were analyzed. Most of the materials selected for the analyses were made from polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS).
The paper presents results of the studies photodegradation, photooxidation, and oxidation of phenylarsonic acid (PAA) in aquatic solution. The water solutions, which consist of 2.7 g dm(-3) phenylarsonic acid, were subjected to advance oxidation process (AOP) in UV, UV/H2O2, UV/O3, H2O2, and O3 systems under two pH conditions. Kinetic rate constants and half-life of phenylarsonic acid decomposition reaction are presented. The results from the study indicate that at pH 2 and 7, PAA degradation processes takes place in accordance with the pseudo first order kinetic reaction. The highest rate constants (10.45 × 10(-3) and 20.12 × 10(-3)) and degradation efficiencies at pH 2 and 7 were obtained at UV/O3 processes. In solution, after processes, benzene, phenol, acetophenone, o-hydroxybiphenyl, p-hydroxybiphenyl, benzoic acid, benzaldehyde, and biphenyl were identified.
Purpose In this paper, an attempt was made to explain the long-lasting occurrence of atrazine in soil. Despite the fact that this herbicide has been banned in European Union 10 years ago, it is still detected in the environment. Materials and methods Soil samples (organic and mineral horizon), SiO 2 and Al 2 O 3 sorbents were spiked with atrazine. The ultrasound-assisted extraction coupled with gas chromatography-electron capture detector was performed to establish the atrazine recovery depending on the type of soil horizon and sorbent. Fourier transform infrared spectroscopy (FTIR) analysis was conducted to determine the type of interactions between atrazine and sorbents. Results and discussion The atrazine recovery was lower for the mineral horizon (15%) compared to the organic horizon (63%). This finding suggests an interaction between atrazine and the mineral components of soil. Therefore, attempts have been made to explain atrazine's interaction with the main mineral components of soil, SiO 2 and Al 2 O 3 , and to investigate the influence of pH on atrazine's behaviour in soil. The atrazine recoveries were 86.5 and 10.7% for Al 2 O 3 and SiO 2 , respectively. The obtained results demonstrated that the protonated atrazine exhibits stronger interactions with the soil mineral layer (recovery below 0.1%) in comparison to molecular form of atrazine (recovery 86%). FTIR results suggested interactions between atrazine and SiO 2 . FTIR analysis revealed that 1,3,5-azidine ring interacts with SiO 2 molecule. Conclusions In acidic soil, atrazine remediation is limited, especially if the soil contains minerals with high SiO 2 contents. This situation may cause the long-lasting persistence of atrazine in soil.
The paper presents the kinetics and proposed pathways photodegradation and photooxidation of p-arsanilic acid, in a neutral environment by ozone and hydrogen peroxide. The results showed that in a neutral environment, photoozonation process was characterized by the highest decomposition rate constant (k) (k = 31.8 × 10(-3) min(-1)). The rate constants decreased in the order UV/O3 > O3 > UV/H2O2 > H2O2 > UV. It was also found that under pH = 7, decomposition of p-arsanilic acid leads mainly to the formation of aniline, which undergoes secondary reactions. Intermediate products of oxidation and photooxidation by hydrogen peroxide like nitrobenzene, nitrophenol, azobenzenes, and phenylazophenol were identified depending on processes. However, in the photodegradation process, formation of nitrasone as a reaction product of p-arsanilic acid with oxygen in the singlet state was observed. In the case of ozonation and photoozonation, in addition, aniline formation of carboxylic acids was observed.
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