Chromatographic Methods for the Determination of Organic Pollution in Urban Water: A Current Mini Review.

The number of pollutants and chemicals with the potential to reach the environment is still largely unknown, which poses great challenges for researchers in various fields of science, environmental scientists, and analytical chemists. Chromatographic techniques, both gas chromatography (GC) and liquid chromatography (LC) coupled with different types of detection, are now invaluable tools for the identification of a wide range of chemical compounds and contaminants in water. This review is devoted to chromatographic techniques GC-MS, GC-Orbitrap-MS, GC-MS/MS, GC-HRMS, GC × GC-TOFMS, GC-ECD, LC-MS/MS, HPLC-UV, HPLC-PDA, UPLC-QTOFMS, used to determinate emerging organic contaminants in aquatic media, mainly in urban water, published in the scientific literature over the past several years. The article also focuses on sample preparation methods used in the analysis of aqueous samples. Most research focuses on minimizing the number of sample preparation steps, reducing the amount of solvents used, the speed of analysis, and the ability to apply it to a wide range of analytes in a sample. This is extremely important in the application of sensitive and selective methods to monitor the status of urban water quality and assess its impact on human health.

Determination of modified nucleosides in the urine of children with autism spectrum disorder.

Metabolic disorders and nutritional deficiencies in ASD children may be identified by the determination of urinary-modified compounds. In this study, levels of selected seven modified compounds: O-methylguanosine, 7-methylguanosine, 1-methyladenosine, 1-methylguanine, 7-methylguanine, 3-methyladenine, and 8-hydroxy-2`-deoxyguanosine in the group of 143 ASD children and 68 neurotypical controls were analyzed. An ancillary aim was to verify if the reported levels differed depending on the pathogenetic scoring of ASD (mild deficit, moderate deficit, severe deficit). Elevated O-methylguanosine and 7-methylguanosine levels and significantly lower levels of 3-methyladenine, 1-methylguanine, 1-methyladenosine, 7-methylguanine, and 8-hydroxy-'2'-deoxyguanosine were observed in ASD children compared to controls. O-methylguanosine levels were elevated in the mild and moderate groups, while the levels of 1-methylguanine, 1-methyladenosine, 7-methylguanine, and 8-hydroxy-'2'-deoxyguanosine in the same groups were lower than in neurotypical controls. The reported evidence shows that modified nucleosides/bases can play a potential role in the pathophysiology of ASD and that each nucleoside/base shows a unique pattern depending on the degree of the deficit.

Relationship between Excreted Uremic Toxins and Degree of Disorder of Children with ASD.

Autism spectrum disorder (ASD) is a complex developmental disorder in which communication and behavior are affected. A number of studies have investigated potential biomarkers, including uremic toxins. The aim of our study was to determine uremic toxins in the urine of children with ASD (143) and compare the results with healthy children (48). Uremic toxins were determined with a validated high-performance liquid chromatography coupled to mass spectrometry (LC-MS/MS) method. We observed higher levels of p-cresyl sulphate (pCS) and indoxyl sulphate (IS) in the ASD group compared to the controls. Moreover, the toxin levels of trimethylamine N-oxide (TMAO), symmetric dimethylarginine (SDMA), and asymmetric dimethylarginine (ADMA) were lower in ASD patients. Similarly, for pCS and IS in children classified, according to the intensity of their symptoms, into mild, moderate, and severe, elevated levels of these compounds were observed. For mild severity of the disorder, elevated levels of TMAO and comparable levels of SDMA and ADMA for ASD children as compared to the controls were observed in the urine. For moderate severity of ASD, significantly elevated levels of TMAO but reduced levels of SDMA and ADMA were observed in the urine of ASD children as compared to the controls. When the results obtained for severe ASD severity were considered, reduced levels of TMAO and comparable levels of SDMA and ADMA were observed in ASD children.

Higher Levels of Low Molecular Weight Sulfur Compounds and Homocysteine Thiolactone in the Urine of Autistic Children.

In this study, the levels of concentration of homocysteine thiolactone (HTL), cysteine (Cys), and cysteinylglycine (CysGly) in the urine of autistic and non-autistic children were investigated and compared. HTL has never been analyzed in autistic children. The levels of low molecular weight sulfur compounds in the urine of both groups were determined by validated methods based on high-performance liquid chromatography with spectrofluorometric and diode-array detectors. The statistical data show a significant difference between the examined groups. Children with autism were characterized by a significantly higher level of HTL (p = 5.86 × 10-8), Cys (p = 1.49 × 10-10) and CysGly (p = 1.06 × 10-8) in urine compared with the control group. A difference in the p-value of <0.05 is statistically significant. Higher levels of HTL, Cys, and CysGly in the urine of 41 children with autism, aged 3 to 17, were observed. The obtained results may indicate disturbances in the metabolism of methionine, Cys, and glutathione in some autistic patients. These preliminary results suggest that further research with more rigorous designs and a large number of subjects is needed.

Analytical Interpretation of Organic Residues From Ceramics As a Source of Knowledge About Our Ancestors.

Food ingredients which were prepared or stored in the archeological ceramics are the most frequently used in the study of ceramic vessels with the use of various types of gas chromatographic methods. These include lipids which contain fatty acids and compounds characteristic of various types of food known as archeological biomarkers. The paper shows how the lipid profile analysis and its interpretation can be helpful to explain the source of organic substances preserved in archeological ceramic vessels. The presence of characteristic sterols discriminates between plant (phytosterols) and animal (zoosterols) residues. Based on the calculated proportions of selected fatty acids, the animal residues can be precisely identified as originating from fish, ruminants or monogastric animals. Many authors have created their own methods of interpretation and conclusion, which makes it possible to sort out all the information gathered about the historical purpose of clay vessels. Due to the fact that the presented research still raises some doubts and questions, it is important for the interpretation of the results of chemical analysis to be considered in the archeological context. The ability to properly explain the meaning of the results of analyses is crucial for a better understanding of the life and customs of our ancestors.

Reduced levels of modified nucleosides in the urine of autistic children. Preliminary studies.

The aim of this study was to investigate and compare the levels of concentration of modified nucleosides in the urine of autistic and healthy children. The compounds have never been analyzed before. The levels of nucleosides in the urine of both groups were determined by validated high performance liquid chromatography coupled to mass spectrometry (LC-MS/MS) method using multiple reaction monitoring (MRM) mode. Chromatographic separation was achieved with HILIC column and tubercidin was used as the internal standard for the quantification of urinary nucleosides. The within run accuracy and precision ranged from 89 to 106% and from 0.8% to 4.9%, respectively. Lower levels of O-methylguanosine, 7-methylguanosine, 1-methyladenosine, 1-methylguanine, 7-methylguanine and 3-methyladenine in the urine of 22 children with autism, aged 3 to 16 were observed. The differences were not observed in 20 healthy volunteers, in a similar age group. These findings show that modified nucleosides there are metabolic disturbances and nutritional deficiencies in autistic children.

The Studies of Archaeological Pottery with the Use of Selected Analytical Techniques.

Modern analytical methods play an important role in archaeological objects, including ceramics. This review focuses on the use of analytical methods such as: gas chromatography coupled mass spectrometry, Fourier transform infrared spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS), powder X-ray diffraction with thermal analysis to study the chemical and mineralogical composition of archaeological samples and organic residues preserved inside. In this paper, special attention was paid to the ToF-SIMS method, which allows the determination of characteristic ions on the surface of ceramic samples.

Different Analytical Procedures for the Study of Organic Residues in Archeological Ceramic Samples with the Use of Gas Chromatography-mass Spectrometry.

The analysis of the composition of organic residues present in pottery is an important source of information for historians and archeologists. Chemical characterization of the materials provides information on diets, habits, technologies, and original use of the vessels. This review presents the problem of analytical studies of archeological materials with a special emphasis on organic residues. Current methods used in the determination of different organic compounds in archeological ceramics are presented. Particular attention is paid to the procedures of analysis of archeological ceramic samples used before gas chromatography-mass spectrometry. Advantages and disadvantages of different extraction methods and application of proper quality assurance/quality control procedures are discussed.