Analytical Chemistry Laboratory Research Articles

The Analysis of Creative and Critical Thinking Abilities of Future Teachers on Analytical Chemistry Laboratory Activity

The ability to think creatively and critically is considered the main cognitive competency. This study aimed to measure the thinking ability of students (n = 33) who participated in a laboratory activity in analytical chemistry. Case study methods were used to collect qualitative data, which supports quantitative data. The student’s creative and critical thinking abilities are measured by correlating the test result with their observations and responses. The results show that the student’s creative and critical thinking abilities are qualified as sufficient. An average of 46.96% of the students could provide correct answers, with the highest percentage on mixture separation tasks (72.7%). The students also showed creative and critical thinking abilities in creating and defining the result after consideration, resolving problems, providing answers with sound reasoning, observing, creating combinations and objects, and detailed ideas regarding the task indicators. The students could also define terms, analyze questions, and adapt their approaches to resolve tasks. The abilities of some students to identify problems from several points of view are still considered low, and they need to be able to identify issues based on given pictures and assess topics from different perspectives. The laboratory activity should create more indicators to think critically and creatively about every aspect. Keywords: creative thinking, critical thinking, abilities of future teachers, analytical chemistry, laboratory activity

АНАЛИЗ УСЛОВИЙ ТРУДА ЛАБОРАНТА ХИМИЧЕСКОГО АНАЛИЗА ГРУППЫ СТОЧНЫХ ВОД НЕФТЕХИМИЧЕСКОГО ПРОИЗВОДСТВА

The article analyzes the working conditions of a chemical analysis laboratory assistant performing analyses of contaminated wastewater in a petrochemical production testing laboratory

Regulamentele și alte acte normative ale municipalității bucureștene referitoare la piețe și hale (1870–1914)

Since 1864, cities have played an increasingly important role in creating the norms and rules that governed human life, from economic activity to leisure. These rules had a very important role in the modernization process, contributing substantially to changing behaviours and practices, creating professional bodies, and adopting Western models. However, in Romanian historiography, this phenomenon is far from receiving the attention it deserves. Our paper aims to analyse the regulations, ordinances, and decisions issued by the Bucharest City Hall, regarding trade carried out in market halls, markets, in various places on the city streets, or by peddlers. Markets and market halls were, in the City Hall's conception, not just places intended for the trade of food and various other goods. They were supposed to be fundamental tools through which the municipality ensured that the citizens of Bucharest had access to safe food – from a hygienic and sanitary point of view – and that the numerous diseases transmitted through food had as few consequences as possible on the health of the capital's inhabitants. To attain this aim, the mayor, the Municipal Council, and the Hygiene Council elaborated and enacted numerous rules, which, under the combined pressure of the city's development, advances in the medical, chemical, and biological sciences, not least the professionalization of the municipal administration, experienced a rapid evolution during the chronologic span discussed. At the same time, the City Hall invested in the creation of an infrastructure that would allow the application of these measures (market halls and market, abattoir, laboratory for chemical and bacteriological analysis, etc.), and a body of officials that would ensure their compliance.

Analysis of aromatic carboxylic acid and calcium salt couples with gas chromatography-mass spectrometry: Implications and comparison with in situ measurements at Mars' surface

Aromatic organic salts such as benzoates or phthalates may be widespread degradation products of organic molecules at the surface of Mars. The low volatility of these aromatic carboxylic salts could have compromised their detection through thermal extraction in situ analyses such as those performed by the Viking landers. However, over the years, analytical chemistry laboratories on board current and future Martian surface missions, such as the Sample Analysis at Mars (SAM) instrument suite on board the Curiosity rover and the Mars Organic Molecule Analyzer (MOMA) instrument of the Rosalind Franklin ExoMars rover, respectively, have evolved. These instruments have improved in efficiency to detect refractory and polar organic compounds, which could influence the detection of aromatic organic salts. To evaluate the capability of detecting aromatic organic salts on Mars with in situ instruments, we performed laboratory experiments under Viking, SAM, and MOMA-like Gas Chromatography-Mass Spectrometry (GC–MS) conditions with two carboxylic acid/salt couples: phthalic acid/calcium phthalate and benzoic acid/calcium benzoate. We studied the behavior and signatures of both molecular forms when using pyrolysis and derivatization experiments and the implications of these results in the search for organic molecules on Mars. This study showed that the Viking experiments could not have detected the presence of aromatic carboxylic salts in Martian samples because its maximum pyrolysis temperature was too low (500 °C). However, we showed that calcium benzoate and calcium phthalate, despite their refractory nature, could be identified indirectly through the detection of thermal and derivatized degradation products, both with SAM and MOMA. No conclusive proof of the presence of these aromatic organic salt species have been found in the SAM in situ data but given the right instrumental set-up they could be detected if present. The conclusions of this work raise essential questions on the detectability of refractory molecules, the analytical efficiency of flight instruments, and the interpretation of in situ data.

Enhanced Heavy Metal Removal from Wastewater Produced by Chemical Analysis Laboratory Using Calcium Oxide Precipitation: pH Improvement and Characterization of Precipitated Phases

This article presents research results on the precipitation of heavy metals: Aluminum (Al), arsenic (As), cadmium (Cd), zinc (Zn), iron (Fe), chromium (Cr), copper (Cu), nickel (Ni), vanadium (V), and molybdenum (Mo) from wastewater generated in mining chemical analysis laboratory. Calcium oxide was used as the precipitating agent. The efficiency of heavy metal removal was achieved by increasing the dosage of precipitating reagent (8-28 g/L). Efficiencies greater than 90% are achieved. The efficiency of chemical precipitation depends on the pH of the process. Over a wide pH range from 6-11, the removal efficiency of zinc, iron, cadmium, and arsenic were approximately 99.9%. The optimum pH range for the removal of most elements was found to be between 8 and 11, where the removal efficiency of heavy metal ions reached up to 99%. Furthermore, X-ray diffraction results indicated that the metals in the wastewater precipitated in various forms as mentioned in Table 7, and not just as hydroxides, due to the presence of different ions in the solution.

Delay in final opinion of autopsy requiring Histo-pathological and chemical analysis

Examination of viscera by pathologist or chemical examiner is a must in cases where the cause of death is not confirmed/ could not be ascertained during the autopsy. Viscera is handed over to police to be taken to respective laboratories for histopathological examination or chemical analysis or for both. This leads to delay in giving the final opinion regarding the cause of death.: To study the delay in giving the final opinion of a particular case from the day of postmortem examination. Study included autopsy cases done in the year 2015 and 2018. The data was collected from the PMR, histopathological and toxicological examination reports and from the final opinion. Delay/ time taken at different levels was studied and the average delay at each level was calculated. Average delay for final opinion was found to be 561 and 378 days for the year 2015 and 2018, respectively. In one case this time taken was more than 7 years. About 63% of the cases studied are still awaiting final disposal.

Construction and Application of Teaching Resources for Inorganic and Analytical Chemistry Laboratory Course in the Context of Digital Empowerment

Construction and Application of Teaching Resources for Inorganic and Analytical Chemistry Laboratory Course in the Context of Digital Empowerment

Utilizing website for analytical and inorganic Chemistry laboratory services

Improving the quality of laboratory services in the Industrial Revolution 4.0 era, one of which is by utilizing information and communication technology or in this study it is called digitization. Digitization is the process of converting information available on paper to a digital format, digitization can be in the form of a website. Utilization of this website will make it easier for students to access the information needed quickly and easily. So far, inventories in analytical and inorganic chemistry laboratories have only been carried out by entering data in a book, and only some of the data has been entered into a simple Excel so it is too complicated and the risk of losing files is very large. Therefore, the use of a centralized website system needs to be done. This study intends to identify the stages involved in creating a website dedicated to the Laboratory of Analytical and Inorganic Chemistry within the Chemistry Department, Faculty of Mathematics and Natural Science at Universitas Negeri Surabaya. Additionally, it aims to assess user reactions to the website. The research methodology employed is the 4D approach, encompassing the Define, Design, Develop, and Disseminate phases. The initiation of the website design process entails the incorporation of various features to enhance its visual appeal. These elements are then used as a basis for coding both the website’s menu and content.

Digital technologies in environmental protection and rational use of natural resources

The main directions and trends in the use of digital technologies in environmental practice are considered. The strategy adopted in the Russian Federation in the field of digital transformation of the ecology and environmental management industry is analyzed. Examples of the use of information methods and tools in environmental technologies are given. The used digital software products are grouped depending on the functionality embedded in them: information and legal systems; software products that implement calculation methods for assessing the impact on the natural environment; software designed for data processing and reporting of chemical analytical laboratories for environmental control and electronic cartographic data in the field of environmental protection. Particular attention is paid to the problems, risks and prospects for the development of information technologies in the field of environmental protection and rational use of natural resources.

Approximation method for the potential composition of petroleum fractions

The paper gives a brief review of mathematical models of potential composition of oil fractions. The stages of obtaining approximating dependence of the fractional composition of oil are defined. A multicomponent mixture is represented as a discrete series of narrow hydrocarbon fractions. Each of them is characterized by its average boiling point. The results of approximation obtained for oil of different fields are given. The criterion for choosing dependence is the sum of squared deviations of factored values from experimental (reference) values. The following approximating dependencies of the curve of true boiling points for oil of different deposits are obtained. They are cubic parabola, power function, arctangence, exponentiation function, cubic parabola-arctangence. It is shown that the best results are obtained for combined ‘cubic parabolaarctangent’ model. In case of data deviation on oil fractional composition coming from chemical analytical laboratory coefficients are corrected in TBP approximation. Oil fractional composition awareness is important when choosing the direction of oil refining, in process and simulation modeling, when determining the top performance of processing units.

Novel derivative compound produced from carbofuran insecticide degradation and transformation promoted by Pseudomonasfluorescens

Carbofuran insecticide is one of the insecticides most often used by Indonesian farmers. The United Nations Environment Program (UNEP) 2011 in the decision of UNEP/FAO/RC/CRC.11/6, agreed that the active ingredient Carbofuran is dangerous to human health and the environment. P. fluorescens bacteria are known to be able to remediate carbofuran-contaminated soil. This study examines more deeply the biodegradation and biotransformation processes of Carbofuran in P. fluorescens bacteria. The research was carried out at the Laboratory of Plant Diseases, Faculty of Agriculture, Brawijaya University; Analytical Chemistry Laboratory, State Polytechnic of Malang; and Analytical Chemistry Laboratory, Udayana University from February to August 2020. The results showed that P. fluorescens was able to degrade the insecticide Carbofuran in liquid media up to 82 % and the growth of P. fluorescens bacteria reached 2.9 x 1012 CFU/mL, bacteria P. fluorescens is able to degrade the insecticide Carbofuran in a mixture of soil and compost up to 85 % and the growth of P. fluorescens bacteria reaches 7.5 x 1013 CFU/mL, resulting in Carbofuran insecticide derivatives from the biotransformation process, there are 3-hydroxy-7-phenol; 2,3-dihydro-1-benzofuran-2,2,7-triol; (2Z)-2-[(2Z)-pent-2-en-1-ylidene]butane-1,4,4-trio; 7-phenol; 2,2,3-trihydroxy-2,3-dihydro-1-benzofuran-7-yl hydrogen carbonate; 2,2-dimethyl-2,3-dihydro-1-benzofuran-7-yl acetate; 7-(hydroxymethoxy)-2,3-dihydro-1-benzofuran-2,2,3,5-tetrol; 3-hidroksi-2-fenilpropil Carbamat; 2-(3-hydroperoxy-2-hydroxyphenyl)ethane-1,1-diol, 3-keto-7-fenol; 4-hydroxy-2,2-dimethyl-2,3-dihydro-1H-inden-1-one; 3-hydroxy-carbofuran; and 7-methoxy-2,2-dimethyl-2,3-dihydro-1-benzofuran-3,5-diol. Carbofuran derivative compounds from the biodegradation of P. fluorescens bacteria are less toxic than the active ingredient Carbofuran.

Assessment of Daylighting in a Historical Educational Building: Ankara University Faculty of Science Analytical Chemistry Laboratory

Assessment of Daylighting in a Historical Educational Building: Ankara University Faculty of Science Analytical Chemistry Laboratory

Water Chemical Analysis of Surface Water Runoff from Iron Ore Mine Void at Tanjung – Bone, South Sulawesi.

The main problem in open-pit mining activities is the remaining mine openings as voids after mining activities end. The interaction between rock, water and air can cause dissolved rock chemical elements to cause polluted water. A study of this phenomenon was carried out in a void in the Tanjung area. An abandoned iron ore mine left a void with a depth of 13 meters. Furthermore, around the void existed two stockpiles of mined ore. Therefore, the void and the stockpiles may act as pollutant sources that can reduce surface water quality. In the rainy season, the water from the void flows out as a runoff downstream through a tributary. This study is intended to analyze the chemical concentration of runoff water from the void. Field observation was done to identify rock formation, and measured pH, turbidity, total dissolved solids (TDS), and electrical conductivity(EC) of water on site, and collected 10 water samples from the river and tributary. Field data was completed with laboratory chemical analysis for water major elements of K+, Na+, Ca2+, Mg2+, Cl−, SO4 2−, CO3 2− and HCO3. The results of the analysis of the TDS test with a minimum value of 4 mg/l and a maximum of 607 mg/l. turbidity value 0 to 21.4 NTU, pH value 2.9 to 8.2, EC value 165.6 ms/cm to 316 ms/cm. Plotting the concentration of the major elements into Trilinear Piper Diagram shows that water is as CaMgSO4 water type based on their major elements. Changes in water quality at voids, stockpiles and areas around the mine indicate that potential water pollution is generated from existing stockpiles.

Analysis of the Active Ingredients in Sunscreen: A Multiweek Experiment for the Analytical Chemistry Laboratory

Analysis of the Active Ingredients in Sunscreen: A Multiweek Experiment for the Analytical Chemistry Laboratory

Birch bud colloid ointment, production technology and therapeutic activity

The successful reproduction of the herd and the growth of livestock productivity is largely hampered by morbidity, i.e.: surgical diseases (bruises, abscesses, bursitis, arthritis, myositis, stretching and rupture of muscles, tendon-ligamentous apparatus, synovial and mucous bags, etc.), breast diseases (injuries, bruises, hematomas, mastitis, etc.). These diseases are still widespread and account for more than 40% of the total number of non-communicable diseases. They cause great economic damage to livestock farms, due to a significant decrease in the productivity of sick animals, the expenditure of material resources for their treatment, premature culling, and often the death of sick animals. Positive results in the fight against this kind of diseases (common characteristic signs of which are – swelling, tension, swelling, soreness with elevated local temperature and functional disorders) that distinguish them into one large group of dangerous diseases can be obtained not only by implementing a complex of general zootechnical and veterinary measures that need to be carried out systematically, on a daily basis, but also by providing drugs with analgesic and anti-inflammatory properties (in combination). The article presents some results of the technology of preparation and therapeutic activity, birch bud colloid ointment, obtained by dispersing birch buds in the laboratory of analytical chemistry and chemical colloids of the Moscow State Medical University, which was insisted on alcohol, mixed into the ointment base and used as stable emulsion ointments. Ointment is a soft dosage form consisting of medicinal substances and a base, intended for application to the skin, wounds or mucous membranes, that is, for external use [2,3].

System for Indoor Comfort and Health Monitoring Tested in Office Building Environment

The use of smart technologies and the Internet of Things (IoT) is becoming more and more popular in order to enhance the overall building performance by monitoring parameters related to occupants’ comfort and health in the built environment. A new modular, custom-made and replicable IoT system is proposed based on an Arduino development board (MKR WiFi 1010) connected to the Arduino IoT Cloud. An Application Programming Interface (API) enables the integration of this system with other possible ones, thus making the system modular, custom-made and replicable. A series of parameters were simultaneously monitored over a 7-day period in two office spaces and a photovoltaic (PV)-testing laboratory. While the meteorological and comfort parameters (temperature, relative humidity, CO2) were monitored in all three spaces, the health parameters (total volatile organic compounds—TVOCs; formaldehyde—HCHO; particulate matter—PM; and radon—222Rn) were monitored only in an office setup located right next to a Chemical Analysis and Testing Laboratory. Generally, the registered values of the health parameters fell within the recommended thresholds. However, the thermal comfort parameters were constantly exceeded: over 90% of the working time in the two office spaces and 83.33% in the PV-testing laboratory. Still, the optimal relative humidity values in the monitored spaces contributed to the discomfort reduction in the occupants. Also, CO2 and TVOCs had some exceptions in particular conditions. CO2 values of up to 1500 ppm due to poor ventilation and TVOC levels of up to 1000 ppb related to chemical experiment development were registered. Also, several other peaks were recorded when monitoring HCHO as well as PM. Thus, special attention must be paid to natural ventilation or to the improvement of building characteristics. Also, the time intervals when experiments in the Chemical Analysis and Testing Laboratory are carried out should be communicated to other personnel from the nearest offices. The testing of the monitoring system over a one-week period showed that the proposed solution operated adequately, representing a reliable tool for data acquisition via the Arduino IoT Cloud.

Investigation of Features of Mass-Fragmentation of Some N-(N,N-diethylacetamidino)-O-alkylfluorophosphates and Related Alkylfluorophosphonates and their Detection by Liquid Chromatography-High Resolution Mass Spectrometry

The timely detection of violations of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction (CWC) requires reliable methods for detecting toxic chemicals that can be used for chemical attacks. The purpose of this investigation is to estimate chromatographic and mass-spectral characteristics of some toxic chemicals recently included into Schedule 1 of the Annex on Chemicals of the CWC, in particular N-(N,N-diethylacetamidino)-methylfluorophosphonate (DEAMP), N-(N,N-diethylacetamidino)-O-methylfluorophosphate (DEAOMP) and N-(N,N-diethylacetamidino)-O-ethylfluorophosphate (DEAOEP) and the improvement of the qualification of the Chemical Analytical Control Laboratory experts taking part in the OPCW Proficiency Tests. Materials and methods. The technique of high efficient liquid chromatography coupled with tandem high resolution mass spectrometry (LC-MS/HRMS) was used during the investigation. The results. The results of optimization of conditions of mass-spectrometric detection, selection of optimal pairs of ion reactions and program of gradient elution during separation of chemicals in reversed-phase liquid chromatography were presented. Presented approach was tested in analysis of model aqueous samples; metrological parameters of detection of compounds were estimated. Conclusion. It was shown during investigation that electrospray ionization mass-spectra of DEAMP, DEAOMP and DEAOEP contain intensive peaks of protonated molecular ions, which after further fragmentation produce characteristic product-ions used for identification and high sensitive detection of parent compounds by LC-MS/HRMS. Limits of detection of DEAMP, DEAOMP and DEAOEP were 1.0 ng/mL, 0.5 ng/mL and 0.5 ng/mL, respectively

Green Analytical Chemistry Laboratory Boxset: From the Lab-at-Home during COVID-19 to a Science Teacher Training

Green Analytical Chemistry Laboratory Boxset: From the Lab-at-Home during COVID-19 to a Science Teacher Training

An investigation into the response of the soil ecological environment to tourist disturbance in Baligou.

The purpose of this study is to understand the response patterns of the soil ecological environment of the Macau Wetland Park to different levels of tourist interference and to provide a scientific basis for the rational development of the Bali Gou ecological tourism plan and the protection and management of the scenic area's ecological environment. Combine the methods of field collection and laboratory physical and chemical data analysis to analyze the impact of the strength of tourism disturbance on the soil ecological environment of Baligou. During the tourist activities in Baligou, the human factors in the process have an impact on the physical aspects of the scenic area's soil, such as soil bulk density, color tone, porosity, compactness, capacity, and leaf litter. In addition, pH value, soil enzyme activity, organic matter, and heavy metals in the soil have caused some interference. The overall data show that the dynamic of soil indicators is background area < buffer area < disturbed area,where the sample area is affected by human trampling and infrastructure construction and other disturbances leading to regular changes in the content of Pb and Cr in the sample soil, while the content of other heavy metals is lower than the national standard.The range of the most extreme values of the SRI integrated soil ecological response evaluation index was A1 disturbance area = 4.679 and C1 background area = 1.263, respectively. The larger the value of the SRI response index, the greater the impact and negative effect of the disturbance influence of tourism activities on the soil ecological environment of the scenic area, and the higher the level of response of the soil ecological environment of the scenic area to the disturbance of tourism activities. Moderate and reasonable tourism development activities play a role in promoting soil quality in scenic areas. Therefore, it is suggested to carry out reasonable ecological environment planning and take certain macro-measures to prevent the deterioration of the soil ecological environment, so as to achieve a win-win situation of ecological environmental protection while developing the tourism economy in scenic areas.

Lead Levels in Hair and Blood of Container Truck Drivers at PT. Trans Indo Sakti Surabaya

Lead is one of the heavy metals used as an additive in gasoline to enhance lubrication and combustion efficiency in motor vehicles, such as container truck drivers, and is commonly found on highways. Truck drivers have a higher tendency to inhale air containing lead while on the road, which can lead to poisoning. Hair and blood can serve as biomarkers of lead exposure in the body. The purpose of this research is to determine the lead levels in the hair and blood of container truck drivers at PT. Trans Indo Sakti Surabaya using Atomic Absorption Spectrophotometry (AAS). This research is a descriptive study conducted at the Analytical Chemistry Laboratory of the Department of Medical Laboratory Technology, Health Polytechnic Ministry of Health Surabaya and the Standardization and Industrial Services Center Laboratory in Surabaya from October 2022 to May 2023. The samples used in the study are 15 container truck drivers, selected using purposive sampling technique. This study demonstrates results of the lowest hair lead level value at 0.1936 µg/g and the highest at 3.026 µg/g. Among the respondents, 9 were categorized as having normal levels, while 6 respondents were categorized as having abnormal levels. For the blood samples, the lowest lead level obtained was 0.146 µg/dL and the highest was 3.81 µg/dL. The lead levels are still categorized as normal. The presence of lead in the body is influenced by age, length of employment, duration of work, and smoking habits.