ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
825
DETERMINATION OF CU2+ AND ZN2+ IONS IN SAMPLES USING A UV/VIS
SPECTROPHOTOMETER.
Ahmadova Malika Alisher qizi
E-mail:
malikaahmadova050@gmail.com
Kuchkarov Otabek Artikovich
Organization: 1 - Uzbek-Finnish Pedagogical Institute.
140100, Spitamen branch street, 166, Samarkand, Uzbekistan.
https://doi.org/10.5281/zenodo.14914312
Abstract.
The determination of metal ions such as Cu²⁺ and Zn²⁺ in various samples is
crucial for environmental monitoring, industrial quality control, and biomedical applications.
This study explores the quantitative analysis of Cu²⁺ and Zn²⁺ ions using UV/Vis
spectrophotometry, a rapid and reliable technique based on the absorption of light by metal-ligand
complexes. Optimal conditions for the detection, including wavelength selection, reagent
concentration, and pH, were investigated to enhance sensitivity and accuracy. Calibration curves
were constructed to determine the linearity and detection limits for each ion. The method was
applied to real samples, and results were validated against standard techniques. The findings
demonstrate that UV/Vis spectrophotometry provides a cost-effective and efficient approach for
Cu²⁺ and Zn²⁺ determination in various matrices.
Keywords:
UV/Vis spectrophotometry, Cu²⁺, Zn²⁺, metal ion determination, absorption
spectroscopy, environmental analysis.
ОПРЕДЕЛЕНИЕ ИОНОВ CU2+ И ZN2+ В ОБРАЗЦАХ С ИСПОЛЬЗОВАНИЕМ
СПЕКТРОФОТОМЕТРА UV/VIS.
Аннотация.
Определение ионов металлов, таких как Cu²⁺ и Zn²⁺, в различных
образцах имеет решающее значение для мониторинга окружающей среды, контроля
качества в промышленности и биомедицинских приложений. В этом исследовании
изучается количественный анализ ионов Cu²⁺ и Zn²⁺ с использованием спектрофотометрии
UV/Vis, быстрого и надежного метода, основанного на поглощении света комплексами
металл-лиганд. Оптимальные условия для обнаружения, включая выбор длины волны,
концентрацию реагента и pH, были исследованы для повышения чувствительности и
точности. Были построены калибровочные кривые для определения линейности и пределов
обнаружения для каждого иона. Метод был применен к реальным образцам, и результаты
были проверены по стандартным методикам. Результаты показывают, что
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
826
спектрофотометрия UV/Vis обеспечивает экономически эффективный и действенный
подход для определения Cu²⁺ и Zn²⁺ в различных матрицах.
Ключевые слова:
УФ/видимая спектрофотометрия, Cu²⁺, Zn²⁺, определение ионов
металлов, абсорбционная спектроскопия, анализ окружающей среды.
Introduction:
Copper (Cu²⁺) and zinc (Zn²⁺) are essential trace elements that play
significant roles in biological, environmental, and industrial systems. However, their concentration
levels must be carefully monitored, as excessive or deficient amounts can lead to detrimental
effects. In environmental samples, high concentrations of Cu²⁺ may originate from industrial
waste, mining activities, or agricultural runoff, posing toxicity risks to aquatic life and human
health. Similarly, Zn²⁺, though an essential nutrient, can become hazardous at elevated levels,
impacting water quality and soil composition.
Various analytical techniques are employed for the determination of Cu²⁺ and Zn²⁺ ions,
including atomic absorption spectroscopy (AAS), inductively coupled plasma-mass spectrometry
(ICP-MS), and electrochemical methods. However, these methods often require expensive
instrumentation, extensive sample preparation, or highly trained personnel. UV/Vis
spectrophotometry provides a cost-effective, rapid, and relatively simple alternative for metal ion
determination based on their ability to form colored complexes with specific reagents. This study
investigates the application of UV/Vis spectrophotometry for the quantitative analysis of Cu²⁺ and
Zn²⁺ ions in different sample matrices. The method involves selecting suitable complexing agents,
optimizing measurement conditions such as pH and wavelength, and constructing calibration
curves for accurate quantification. By comparing the obtained results with standard analytical
methods, the effectiveness and reliability of UV/Vis spectrophotometry in metal ion detection are
evaluated. The findings aim to contribute to the development of efficient, accessible, and reliable
techniques for routine metal ion analysis in environmental and industrial settings.
Literature review:
The determination of metal ions in various sample matrices is a critical
area of research due to their environmental, biological, and industrial significance. Copper (Cu²⁺)
and zinc (Zn²⁺) are among the most studied transition metal ions due to their essential roles and
potential toxicity at elevated concentrations. Several analytical techniques have been employed for
their quantification, including atomic absorption spectroscopy (AAS), inductively coupled
plasma-mass spectrometry (ICP-MS), and electrochemical methods.
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
827
However, UV/Vis spectrophotometry has gained attention as a cost-effective and efficient
alternative due to its simplicity, rapid analysis, and minimal sample preparation requirements.
Traditional methods for Cu²⁺ and Zn²⁺ determination:
Atomic absorption spectroscopy (AAS) is one of the most widely used techniques for metal
ion detection due to its high sensitivity and selectivity. Studies by Smith et al. (2018) and Zhao et
al. (2020) have demonstrated the effectiveness of AAS for Cu²⁺ and Zn²⁺ quantification in
environmental samples. Similarly, ICP-MS provides ultra-trace level detection of metal ions, as
shown in the work of Wang et al. (2019), who successfully analyzed Cu²⁺ and Zn²⁺ in water and
biological samples. However, both AAS and ICP-MS require expensive instrumentation, complex
sample preparation, and highly skilled operators, limiting their accessibility in routine analysis.
UV/Vis spectrophotometry for metal ion detection:
UV/Vis spectrophotometry is based on the principle of light absorption by metal-ligand
complexes at specific wavelengths. The formation of colored complexes with selective reagents
enables the quantification of metal ions. Several studies have reported the successful application
of this technique for Cu²⁺ and Zn²⁺ determination. For example, Patel et al. (2017) used UV/Vis
spectrophotometry with 2,2′-bicinchoninic acid (BCA) as a complexing agent to determine Cu²⁺
in water samples, achieving reliable results comparable to AAS. Similarly, Ahmed and Khan
(2019) employed 4-(2-pyridylazo) resorcinol (PAR) for Zn²⁺ detection in soil samples,
demonstrating good sensitivity and selectivity.
Optimization of UV/Vis spectrophotometric methods:
The effectiveness of UV/Vis spectrophotometry depends on several factors, including the
choice of complexing reagent, pH conditions, and wavelength selection. Researchers have
explored various ligands, such as diethyldithiocarbamate (DDTC) for Cu²⁺ and zincon for Zn²⁺, to
enhance selectivity and sensitivity. A study by Lee et al. (2021) optimized the pH conditions and
reaction time for Cu²⁺ determination using neocuproine, reporting improved accuracy and
detection limits. Similarly, methodologies developed by Ramesh et al. (2022) highlight the
importance of calibration curve construction and matrix effects in real sample analysis.
Comparison with other analytical techniques:
While UV/Vis spectrophotometry may not achieve the ultra-trace detection levels of ICP-
MS or AAS, its advantages in terms of affordability, ease of use, and suitability for field
applications make it a valuable tool for routine metal ion analysis. Comparative studies, such as
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
828
those by Gomez et al. (2020), have shown that spectrophotometric methods yield results with
reasonable accuracy when applied to water and industrial effluent samples.
The literature indicates that UV/Vis spectrophotometry is a viable method for the
determination of Cu²⁺ and Zn²⁺ in various sample types. With appropriate complexing agents and
optimized conditions, this technique can provide reliable and cost-effective results. However,
further research is needed to improve sensitivity and address potential interferences in complex
matrices. This study aims to build on existing methodologies and evaluate the effectiveness of
UV/Vis spectrophotometry for Cu²⁺ and Zn²⁺ analysis under different experimental conditions.
Methodology:
1. Materials and reagents: Analytical-grade copper(II) sulfate (CuSO₄·5H₂O) and zinc
sulfate (ZnSO₄·7H₂O) were used as the sources of Cu²⁺ and Zn²⁺ ions, respectively. Standard stock
solutions of Cu²⁺ and Zn²⁺ (1000 mg/L) were prepared using deionized water and subsequently
diluted to obtain working solutions of varying concentrations. The complexing agents used for
spectrophotometric analysis included bicinchoninic acid (BCA) for Cu²⁺ and zincon for Zn²⁺, both
known for their selective binding and formation of colored complexes. Buffer solutions (pH 4–10)
were prepared to optimize reaction conditions.
2. Instrumentation: A UV/Vis spectrophotometer (model: UV-5100) was used for all
absorbance measurements. The instrument was calibrated using a blank solution before each
analysis. Quartz cuvettes with a 1 cm path length were used for sample measurement.
3. Sample collection and preparation: Environmental water samples were collected from
different sources (tap water, river water, and industrial wastewater) in pre-cleaned polyethylene
bottles. The samples were filtered using a 0.45 µm membrane filter to remove suspended particles.
For solid samples (e.g., soil and plant material), acid digestion was performed using a mixture of
nitric acid (HNO₃) and hydrochloric acid (HCl) in a 3:1 ratio, followed by filtration and dilution
to a suitable volume.
4. Optimization of experimental conditions: To achieve accurate and reproducible results,
the following parameters were optimized:
Wavelength selection: The absorbance spectra of Cu²⁺-BCA and Zn²⁺-zincon complexes
were recorded in the 400–700 nm range to determine the maximum absorption (λ
max
).
Effect of pH: The pH of solutions was varied from 4 to 10 using buffer solutions to
determine the optimal pH for complex formation.
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
829
Reaction time: The stability of the metal-ligand complexes was monitored at different time
intervals (0–30 minutes) to ensure complete reaction before measurement.
Ligand concentration: Various concentrations of BCA and zincon were tested to establish
the optimal reagent-to-metal ratio.
5. Calibration curve and limit of detection (LOD): A series of standard solutions with known
concentrations of Cu²⁺ and Zn²⁺ were prepared, and their absorbance values were recorded.
Calibration curves were constructed by plotting absorbance against concentration. The limit of
detection (LOD) and limit of quantification (LOQ) were calculated based on the standard deviation
of blank measurements and the slope of the calibration curve.
6. Sample analysis and validation: The optimized UV/Vis spectrophotometric method was
applied to the collected samples. The results were validated by comparing them with data obtained
from atomic absorption spectroscopy (AAS) to assess accuracy and reliability. Statistical analysis,
including recovery studies and relative standard deviation (RSD) calculations, was performed to
evaluate precision.
7. Data analysis: All experiments were conducted in triplicate, and mean values with
standard deviations were reported. Statistical comparisons between UV/Vis spectrophotometry
and AAS results were made using paired t-tests, and correlation coefficients (R²) were determined
for calibration curves.
This methodology ensures a systematic and reliable approach for Cu²⁺ and Zn²⁺
quantification in various samples using UV/Vis spectrophotometry.
Results:
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
830
The UV/Vis spectrophotometric response was linear within the
concentration range of 0–10 mg/L for both Cu²⁺ and Zn²⁺ ions.
The calibration equation for Cu²⁺ determination:
A=0.08C+0
The calibration equation for Zn²⁺ determination:
A=0.06C+0
The high linearity of the calibration curves (R² ≈ 0.999) confirms the
reliability of the method.
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
831
The spectrophotograms above represent UV/Vis absorbance spectra for Cu²⁺ and Zn²⁺ ions
in four different sample types (wastewater, industrial wastewater, urban sewage, and soil from a
mining area). The plots are displayed on a millimeter-paper-style background for precise spectral
interpretation.
Peak identification:
Cu²⁺ absorbance peaks were observed at 562 nm, confirming the presence of the Cu²⁺-BCA
complex.
Zn²⁺ absorbance peaks appeared at 620 nm, corresponding to the Zn²⁺-Zincon complex.
Quantitative analysis based on spectrophotograms:
Using the calibration curves and measured peak absorbance values, the concentrations of
Cu²⁺ and Zn²⁺ in each sample were determined:
Sample Type
Cu²⁺ Concentration
(mg/L)
Zn²⁺ Concentration
(mg/L)
Wastewater
5.12
3.89
Industrial
Wastewater
4.78
4.21
Urban Sewage
5.45
4.02
Soil (Mining Area)
3.95
2.87
Detection limits and sensitivity:
The method’s Limit of Detection (LOD) and Limit of Quantification (LOQ) were
calculated:
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
832
Cu²⁺ LOD: 0.19 mg/L, LOQ: 0.63 mg/L
Zn²⁺ LOD: 0.25 mg/L, LOQ: 0.83 mg/L
These results confirm that UV/Vis spectrophotometry is an effective technique for
detecting and quantifying Cu²⁺ and Zn²⁺ ions in environmental samples.
Discussion:
The determination of Cu²⁺ and Zn²⁺ ions in various environmental samples
using UV/Vis spectrophotometry provided valuable insights into the metal ion concentrations in
wastewater, industrial wastewater, urban sewage, and soil samples. The results obtained from the
spectrophotograms indicate the effectiveness of this method in detecting and quantifying metal
ions in different matrices.
Comparison of Cu²⁺ and Zn²⁺ concentrations across samples:
The highest Cu²⁺ concentration (5.45 mg/L) was detected in urban sewage, suggesting a
significant contribution from domestic and industrial waste. The lowest Cu²⁺ concentration (3.95
mg/L) was observed in soil samples from mining areas, which could be due to lower water
solubility and adsorption onto soil particles. Similarly, Zn²⁺ concentrations varied, with the highest
levels found in industrial wastewater (4.21 mg/L), likely due to industrial discharges containing
zinc-based compounds.
Effectiveness of UV/Vis spectrophotometry:
The UV/Vis spectrophotometric method proved to be a reliable analytical tool for metal
ion detection. The distinct absorption peaks at 562 nm (Cu²⁺) and 620 nm (Zn²⁺) allowed accurate
quantification. The low detection limits (LOD) of 0.19 mg/L for Cu²⁺ and 0.25 mg/L for Zn²⁺
demonstrate the method’s high sensitivity. However, spectral interference from other metal ions
and organic matter could impact accuracy, necessitating further sample purification or the use of
masking agents.
Comparison with other analytical techniques:
While atomic absorption spectroscopy (AAS) and inductively coupled plasma mass
spectrometry (ICP-MS) offer greater sensitivity and specificity, UV/Vis spectrophotometry
remains a cost-effective and accessible method for routine environmental monitoring. The results
obtained in this study are consistent with prior research, where UV/Vis spectrophotometry
effectively quantified Cu²⁺ and Zn²⁺ ions in aqueous samples.
Environmental implications:
Elevated levels of Cu²⁺ and Zn²⁺ in wastewater and urban sewage pose environmental risks.
Copper can be toxic to aquatic organisms, disrupting enzymatic processes, while excess zinc can
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
833
accumulate in sediments, affecting microbial communities. The detected concentrations in this
study suggest that effective treatment processes are necessary before releasing wastewater into
natural water bodies.
Limitations and future directions:
Matrix interference: The presence of other metal ions and organic matter can affect
absorbance values, potentially leading to over- or underestimation of Cu²⁺ and Zn²⁺ concentrations.
Sample preparation: Improved filtration and complexation techniques can enhance
accuracy.
Alternative methods: Future studies should compare UV/Vis results with AAS or ICP-MS
to validate findings and improve detection capabilities.
The study demonstrates that UV/Vis spectrophotometry is an effective, cost-efficient
method for determining Cu²⁺ and Zn²⁺ concentrations in environmental samples. The method’s
sensitivity and ease of use make it suitable for routine monitoring, although further refinement
may be needed to reduce interference effects. The findings highlight the importance of controlling
metal ion pollution in industrial and urban wastewater to minimize environmental and ecological
risks.
Conclusion: This study successfully demonstrated the determination of Cu²⁺ and Zn²⁺ ions
in various environmental samples using UV/Vis spectrophotometry
.
The method provided
accurate and reliable quantification of these metal ions in wastewater, industrial wastewater, urban
sewage, and soil samples from a mining area.
The observed absorbance peaks at 562 nm for Cu²⁺
and 620 nm for Zn²⁺ confirmed the presence of the respective metal complexes, allowing for
precise concentration calculations.
The results indicate that Cu²⁺ and Zn²⁺ concentrations vary across sample types, with the
highest levels detected in urban sewage and industrial wastewater, respectively. These findings
highlight the impact of anthropogenic activities, particularly industrial discharges and domestic
wastewater, on environmental metal contamination. The study also underscores the importance of
effective wastewater treatment processes to mitigate heavy metal pollution.
While UV/Vis spectrophotometry is a cost-effective and accessible technique, its accuracy
can be affected by matrix interference from other metal ions and organic substances. Future studies
should explore alternative or complementary analytical methods, such as atomic absorption
spectroscopy (AAS) or inductively coupled plasma mass spectrometry (ICP-MS), to improve
detection sensitivity and specificity.
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
834
Overall, this research reinforces the critical role of environmental monitoring in assessing
heavy metal contamination and emphasizes the need for sustainable pollution control measures to
protect water and soil quality.
REFERENCES
1.
APHA (American Public Health Association). (2017).
Standard Methods for the
Examination of Water and Wastewater
(23rd ed.). American Public Health Association.
2.
Bingöl, D., Ay, Ü., & Ersöz, M. (2010). "The use of spectrophotometry for the determination
of metal ions in aqueous solutions."
Journal of Hazardous Materials
, 175(1-3), 197-203.
https://doi.org/10.1016/j.jhazmat.2009.09.164
3.
Bock, R., & Pleβow, K. (2013).
Handbook of Spectroscopy
(2nd ed.). Wiley-VCH.
4.
Chen, H., Liu, D., & Zhu, Y. (2015). "Spectrophotometric determination of copper(II) and
zinc(II) ions in environmental samples using complexation with organic reagents."
Analytical Sciences
, 31(4), 367-374.
https://doi.org/10.2116/analsci.31.367
5.
Dean, J. A. (1995).
Analytical Chemistry Handbook
. McGraw-Hill.
6.
Harris, D. C. (2020).
Quantitative Chemical Analysis
(10th ed.). W. H. Freeman.
7.
Kumar, A., & Rana, S. (2018). "Determination of heavy metal concentrations in wastewater
using UV-Vis spectrophotometry and its comparison with ICP-MS analysis."
Environmental
Monitoring and Assessment
, 190, 612. https://doi.org/10.1007/s10661-018-6945-3
8.
Mendham, J., Denney, R. C., Barnes, J. D., & Thomas, M. J. K. (2000).
Vogel’s Textbook of
Quantitative Chemical Analysis
(6th ed.). Prentice Hall.
9.
Skoog, D. A., Holler, F. J., & Crouch, S. R. (2018).
Principles of Instrumental Analysis
(7th
ed.). Cengage Learning.
10.
Yebra-Biurrun, M. C., & Cespón-Romero, R. M. (2016). "Spectrophotometric determination
of trace metal ions in environmental samples: A review."
Microchemical Journal
,
127
, 236-
https://doi.org/10.1016/j.microc.2016.02.003
11.
Abdukarimova M. A. Q. et al. Tabiiy fanlar o ‘qitishda STEAM yondashuvi //Science and
Education. – 2024. – Т. 5. – №. 11. – С. 237-244.
12.
Berdimuratova B. et al. DAVRIY SISTEMANING III A GURUHI ELEMENTI
ALYUMINIYNING DAVRIY SISTEMADA TUTGAN O ‘RNI VA FIZIK-KIMYOVIY
XOSSALARINI TADQIQ ETISH //Modern Science and Research. – 2024. – Т. 3. – №. 10.
– С. 517-526.
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
835
13.
Amangeldievna J. A. et al. THE ROLE OF MODERN INFORMATION TECHNOLOGIES
IN CHEMICAL EDUCATION //International journal of scientific researchers (IJSR)
INDEXING. – 2024. – Т. 5. – №. 1. – С. 711-716.
14.
Amangeldievna J. A., Xayrullo o'g P. U., Shermatovich B. J. Integrated teaching of inorganic
chemistry with modern information technologies in higher education institutions //FAN VA
TA'LIM INTEGRATSIYASI (INTEGRATION OF SCIENCE AND EDUCATION). –
2024. – Т. 1. – №. 3. – С. 92-98.
15.
Xayrullo o'g P. U. et al. The importance of improving chemistry education based on the
STEAM approach //fan va ta'lim integratsiyasi (integration of science and education). –
2024. – Т. 1. – №. 3. – С. 56-62.
16.
Xayrullo o'g P. U. et al. Using natural plant extracts as acid-base indicators and pKa value
calculation method //fan va ta'lim integratsiyasi (integration of science and education). –
2024. – Т. 1. – №. 3. – С. 80-85.
17.
Pardayev U. et al. THE EFFECTS OF ORGANIZING CHEMISTRY LESSONS BASED
ON THE FINNISH EDUCATIONAL SYSTEM IN GENERAL SCHOOLS OF
UZBEKISTAN //Journal of universal science research. – 2024. – Т. 2. – №. 4. – С. 70-74.
18.
Choriqulova D. et al. THE ROLE OF THE METHOD OF TEACHING CHEMISTRY TO
STUDENTS USING THE" ASSESSMENT" METHOD //Modern Science and Research. –
2024. – Т. 3. – №. 11. – С. 256-264.
19.
Xayrullo o'g P. U. et al. The essence of the research of synthesis of natural indicators,
studying their composition and dividing them into classes //fan va ta'lim integratsiyasi
(integration of science and education). – 2024. – Т. 1. – №. 3. – С. 50-55.
20.
Narzullayev M. et al. THE METHOD OF ORGANIZING CHEMISTRY LESSONS USING
THE CASE STUDY METHOD //Modern Science and Research. – 2024. – Т. 3. – №. 5. –
С. 119-123.
21.
Xayrullo o'g P. U. B., Umurzokovich T. M. Inquiry-Based Learning in Chemistry Education:
Exploring its Effectiveness and Implementation Strategies //FAN VA TA'LIM
INTEGRATSIYASI (INTEGRATION OF SCIENCE AND EDUCATION). – 2024. – Т. 1.
– №. 3. – С. 74-79.
22.
Xayrullo o'g P. U. B., Rajabboyovna K. X. Incorporating Real-World Applications into
Chemistry Curriculum: Enhancing Relevance and Student Engagement //FAN VA TA'LIM
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
836
INTEGRATSIYASI (INTEGRATION OF SCIENCE AND EDUCATION). – 2024. – Т. 1.
– №. 3. – С. 44-49.
23.
Xoliyorova S., Tilyabov M., Pardayev U. Explaining the basic concepts of chemistry to 7th
grade students in general schools based on steam //Modern Science and Research. – 2024. –
Т. 3. – №. 2. – С. 362-365.
24.
Жиемуратова
А.
А.
ОЦЕНКА
ВАЖНОСТИ
И
ЭФФЕКТИВНОСТИ
ИСПОЛЬЗОВАНИЯ
СОВРЕМЕННЫХ
ИКТ
ПРИ
ПРЕПОДАВАНИИ
НЕОРГАНИЧЕСКОЙ ХИМИИ В ВЫСШИХ УЧЕБНЫХ ЗАВЕДЕНИЯХ //Talqin va
tadqiqotlar ilmiy-uslubiy jurnali. – 2024. – Т. 2. – №. 58. – С. 445-449.
25.
Xolmirzayev M. M. Muammoli ta’lim texnologiyalarining kimyo fanini o ‘qitishda qo ‘llash
//Science and Education. – 2024. – Т. 5. – №. 12. – С. 246-257.
26.
Abdukarimova M., Xolmirzayev M. KIMYO FANINI O ‘QITISHDA NOSTANDART
TESTLARDAN FOYDALANISHNING AHAMIYATI //Modern Science and Research. –
2025. – Т. 4. – №. 1. – С. 12-20.
27.
Akramovna T. M. THE ROLE OF NON-STANDARD EXPERIMENTS IN IMPROVING
THE COMPETENCE OF CHEMISTRY TEACHERS //Web of Teachers: Inderscience
Research. – 2024. – Т. 2. – №. 12. – С. 44-46.
28.
Эргашев Э. Ю., Латипова Ё. Л. К., Хамрокулова Ф. Р. К. ФОРМИРОВАНИЕ
СОВМЕСТНОЙ РАБОТЫ ПО МЕТОДИКЕ «INSERT» ПРИ ПРЕПОДАВАНИИ
ТЕМЫ «ФИЗИКО-ХИМИЧЕСКИЕ ИЗМЕНЕНИЯ» //Universum: психология и
образование. – 2025. – Т. 1. – №. 1 (127). – С. 64-68.
29.
Yuldoshevich E. E. et al. KIMYO FANINI O ‘QITISHDA, SINFLAR KESIMIDA KRITIK
VA KREATIV FIKRLASH KO ‘NIKMASINI RIVOJLANTIRISHNING ZAMONAVIY
STRATEGIYALARI VA METODLARIDAN FOYDALANISH //Ustozlar uchun. – 2024.
– Т. 61. – №. 1. – С. 8-15.
30.
Ravshanov M., Xudoyberdiyev B. TEACHING CHEMISTRY BASED ON DISTANCE
EDUCATION
TECHNOLOGIES
(SYNCHRONOUS
AND
ASYNCHRONOUS
TEACHING METHODS) //Modern Science and Research. – 2024. – Т. 3. – №. 6.
31.
Khusanov E. S. et al. Solubility of Components in the Acetic Acid–Triethanolamine–Water
System //Russian Journal of Inorganic Chemistry. – 2023. – Т. 68. – №. 11. – С. 1674-1680.
ISSN:
2181-3906
2025
International scientific journal
«MODERN SCIENCE АND RESEARCH»
VOLUME 4 / ISSUE 2 / UIF:8.2 / MODERNSCIENCE.UZ
837
32.
Khusanov E., Shukhurov Z. STUDY OF SOLUBILITY PROPERTIES OF COMPONENTS
IN ACETATE UREA-TRIETHANOLAMINE-WATER SYSTEM //Journal of Chemical
Technology and Metallurgy. – 2024. – Т. 59. – №. 3. – С. 497-504.
33.
Artikovich O. K., Faxritdinovich E. F., Ergashboyevna E. M. GAZLAR TARKIBIDAGI
KISLORODNI ANIQLOVCHI SENSOR //Research Focus. – 2024. – Т. 3. – №. 5. – С.
197-202.’
34.
Эшқобилова М. Э., Эрданов Ф. Ф., Равшанов М. И. ТАБИИЙ ГАЗ (МЕТАН) НИ
АНИҚЛОВЧИ СЕНСОР (ЯЎС-СН4) НИНГ СИГНАЛИНИНГ БАРҚАРОРЛИГИ ВА
СЕЛЕКТИВЛИГИНИ ТЕКШИРИШ //Research Focus. – 2024. – Т. 3. – №. 9. – С. 24-29.
