The potential of graphene as an adsorbent for five pesticides from different classes in rape oil samples using dispersive solid-phase extraction

Isolation conditions for five pesticides (metazachlor, tebuconazole, λ-cyhalothrin, chlorpyrifos, and deltamethrin) from rape oil samples were examined using the dispersive solid-phase graphene extraction technique. To determine the optimal extraction conditions, a number of experimental factors (amount of graphene, amount of salt, type and volume of the desorbing solvent, desorption time with and without sonication energy, and temperature during desorption) were studied. The compounds of interest were separated and detected by an HPLC-UV employing a Kinetex XB-C18 column and a mobile phase consisting of acetonitrile and water flowing in a gradient mode. The optimized extraction conditions were: the amount of graphene 15 mg, desorbing solvent (acetonitrile) 5 mL, time desorption 10 min at 40°C, and amount of NaCl 1 g. The detection limit for metazachlor, tebuconazole, λ-cyhalothrin, and chlorpyrifos was 62.5 ng·g−1, and for deltamethrin, it was 500 ng·g−1. The obtained results lead to the conclusion that graphene may be successfully used for the isolation of the five pesticides from rape oil. However, their determination at low concentration levels, as they occur in real oil samples, requires the employment of appropriately highly sensitive analytical methods, as well as a more suitable graphene form (e.g., magnetically modified graphene)

A simple, fast, and green oil sample preparation method for determination of cannabidioloic acid and cannabidiol by HPLC-DAD

Currently, the medical use of food supplements containing Cannabis sativa has attracted the interest of consumers, as well as the medical and scientific community. With the increasing consumption of these products, there is also a risk of their abuse or discrepancy between the actual and declared contents of active substances by the manufacturer in these products. Thus, the development and elaboration of analytical procedures for determination of appropriate phytocannabinoids seems to be important. This work focuses on the development of a simple, fast and environmentally friendly liquid-liquid extraction method combined with fat freezing from an oil sample to isolate two phytocannabinoids: cannabidiol (CBD) and cannabidiolic acid (CBDA). The extraction method was optimized considering efficacy and repeatability of extraction, as well as minimalizing use of organic reagents and sample amount. Under the optimized conditions, extraction recovery for CBD was 97.3–109% and for CBDA was 69.1–69.5% with precision (RSD, %) 5.0–8.4 and 7.1–10.6, respectively. The evaluated main analytical parameters of the developed high pressure liquid chromatography with diode array detector (HPLC-DAD) method for both studied cannabinoids are satisfactory. The usability of the developed method was checked by analysis of real samples of a food supplement–hemp oil enriched with CBD

Influence of tobacco smoke on the pharmacokinetics of citalopram and its enantiomers

The purpose of this study was to evaluate the influence of tobacco smoke on the pharmacokinetics of citalopram (CIT) and desmethylcitalopram (DCIT) and its enantiomers on an animal model. High performance liquid chromatography (HPLC) with a diode array detector (DAD) was used for the identification and quantification of the studied compounds. The HPLC quantification of racemic mixtures of CIT was performed on a C18 column. The limits of detection (LOD) and quantification (LOQ) were: 7 and 10 ng/ml respectively. HPLC separation of citalopram enantiomers (S- and R-CIT) was performed on a Chirobiotic V column. The limits of detection (LOD) and quantification (LOQ) were: 6 and 15 ng/ml for R- and S-CIT respectively. The experiment was carried out on male Wistar rats. The rats were exposed to tobacco smoke for five days (6 hours per day). After the exposure, citalopram was administered in a dose of 10 mg/kg intragastrically. In the control group (non-exposed animals), citalopram was administered in the same way and at an equal dose. The blood of the animals was collected at nine time points. It was found that tobacco smoke exposure inhibits the biotransformation of citalopram. The half-life of the racemic mixture of citalopram after intragastric administration was increased by about 287%. Changes in the pharmacokinetic parameters of S-citalopram (active isomer) show a similar tendency to those of the racemic mixture. The pharmacokinetics of R-citalopram showed no statistically important differences after tobacco smoke exposure. Alterations in the pharmacological parameters of desmethylcitalopram presented an opposite trend to the parent drug. After exposure to tobacco smoke, the induction of metabolism of this compound was observed

Effects of excessive alcohol drinking on nicotine biotransformation in rats

Alcohol and nicotine (tobacco smoke) are often used together, and taking both addictive substances is associated with an increased risk of certain diseases. It is extremely important to understand the pharmacodynamic and pharmacokinetic mechanisms of the interaction between nicotine and ethanol, which are still not fully understood. The study aimed to evaluate the influence of chronic alcohol consumption on nicotine biotransformation in ethanol-preferring and non-preferring male and female rats. Rats were divided into four groups depending on their alcohol preferences and gender. Nicotine, nornicotine, nicotine N-oxide, cotinine, trans-3'-hydroxycotinine, and cotinine N-oxide in rats plasma were determined by LC–MS/MS after five days of exposure to tobacco smoke. A non-compartmental analysis of nicotine and its metabolites was used for pharmacokinetic parameters calculation. Our experimental results showed that the rate of nicotine elimination depends on gender, regardless of alcohol preferences (significantly slower in females than in males). Mean residence timeof nornicotine, cotinine, and trans-3'-hydroxycotinine were significantly higher in alcohol-preferring male rats than in alcohol preferring female rats. In non-alcohol preferring female rats compared to ethanol-preferring female rats, significantly more nicotine N-oxide (fivefold) and trans-3'-hydroxycotinine (twofold) reached the general circulation unchanged. Drinking ethanol influenced the elimination of nornicotine and cotinine in male rats. Ethanol consumption was identified as a modifier of nicotine pharmacokinetics and this was gender-dependent

The influence of prenatal exposure to tobacco smoke on neonatal body proportions

The objective of this study was to determine neonatal anthropometric indices such as: birth weight, crown-heel length, head and chest circumference and ponderal index , in relation to the maternal smoker status (active and passive smoking). The study included 147 neonates born in 2003-2004 at the Princess Anna Mazowiecka University Hospital in Warsaw admitted to the Neonatal and Intensive Care Department of Warsaw Medical University. Neonates were assigned to one of three groups: babies of mothers who were active smokers, passive smokers and non-smokers based on a questionnaire concerning exposure to tobacco smoke and on the concentration of cotinine in maternal urine. The babies of mothers who were active smokers were born with lower birth weight (p=0.033), lower crown-heel length (p=0.026), lower head circumference (p=0.002) and lower chest circumference (p=0.021) significantly more often than babies of non-smoker mothers. Babies whose mothers were active smokers had an increased risk of lower head circumference or 3, 9 (1, 4-10, 7, CI 95%), and an increased risk of lower chest circumference OR 4, 0 (1, 5-10, 9, CI 95%). The babies of mothers who were passive smokers also had lower anthropometric indices, but the differences were not statistically significant. No effect on ponderal index was observed among the neonates whose mothers were active and passive smokers. Smoking during pregnancy causes symmetrical restriction of intrauterine growth

The impact of intrauterine tobacco exposure on the cerebral mass of the neonate based on the measurement of head circumference

The objective of the study was to assess cerebral mass, based on head circumfer- ence measurements in neonates exposed to tobacco smoke in utero, and to deter- mine the relative proportions of the cerebral and body mass. The study included 147 neonates born in the period 2003–2004 at the Princess Anna Mazowiecka University Hospita land admitted to the Neonatal and Intensive Care Department of the Medical University in Warsaw. Subjects were divided into three groups on the basis of maternal status as active, passive, or nonsmokers determined by materna lurinary cotinine concentration and a questionnaire. Neonates whose mothers were active smokers throughout the whole period of pregnancy had a lower head circumference and in consequence a lower cerebral mass significantly more frequently when compared with those whose mothers were nonsmokers, P=0.002. (Median difference in cerebral mass was 48.27 g.) The risk of lower cerebral mass was 3.9 (1.4–10.8, CI 95%) in the group of neonates whose mothers actively smoked cigarettes during pregnancy. A negative correlation was seen between cerebral mass and maternal urinary cotinine concentration (correlation coefficient r=−23, P=0.006). The ratio of the cerebral to body mass was similar for neonates in all three groups. Active smoking during pregnancy had a negative effect on the cerebral mass of theneonate, however no such effect was observed in neonates whose mothers were passive smokers. The deficiency in cerebral mass increased with greater smoking intensity. Active smoking by the mother during pregnancy inhibits the growth of the brain as well as that of the body mass of the neonate

Iron, zinc, copper, manganese and chromium in green teas, their transfer to extracts and correlations between contents of elements and bioactive compounds

Green tea is used worldwide in the preparation of beverages, but also its extracts rich in bioactive compounds, especially flavan-3-ols, are of increasing interest. In addition to bioactive molecules, green tea represents a source of dietary elements. However, knowledge about their content in extracts is limited. The aim of our research was to determine the extent of transfer of selected elements, i.e., iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), and chromium (Cr), from green teas to their extracts and to investigate whether the main bioactive compounds of the extracts affect this transfer. Twelve commercially available green teas were used in the study. The contents of elements in green teas and their extracts obtained with 80% acetone (v/v) were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). High performance liquid chromatography in reverse phase (RP-HPLC) was used to determine contents of caffeine, (–)-epigallocatechin (EGC), (–)-epicatechin (EP), (–)-epigallocatechin gallate (EGCG), and (–)-epicatechin gallate (ECG). The element with the highest content in green teas was Mn (711–1402 µg/g), but its transfer to extracts was the lowest (0.269–0.646%). The mean Fe transfer, second abundant element in teas (115–725 µg/g), was 5.52%. The contents of Mn and Fe in extracts were 5.08–30.2 and 10.7–90.1 µg/g, respectively. Zn, Cu, and Cr were transferred with means of 10.4, 20.0, and 26.2%, respectively, which resulted in their contents in the extracts in the ranges of 5.03–12.6, 1.93–13.8, and 0.128–2.03 µg/g, respectively. The significant positive correlations of Zn content in extracts and/or transfer to extracts with EGCG, EGC and total flavan-3-ols as well as between the same Fe variables and EGC were determined, which suggested that these flavan-3-ols may positively affect the transfer of Fe and Zn from green tea to extracts. In turn, significant but negative correlations were found in the case of Mn and Cu. Future research is needed to identify the causes of the various transfer rate of elements from green teas to extracts