In your own words, describe the specifics of what this study involved. What where the samples? How were they grouped? What analysis did they complete? Under what conditions? For how long? What was measured? What was being compared?

Critical Reflection of a Journal Article (USE THIS AS A GUIDE –  REFERENCE THE SAME ARTICLE)

Summarizing research articles will help you to develop your critical thinking skills and your ability to express yourself in the written form. A research article is written to get across a lot of information quickly to a reader. Reading such articles can be tedious and sometimes frustrating unless you are familiar with scientific writing and the reasons for this style. Research articles are highly structured to make information easy to find. Unlike literary writing, scientific writing emphasizes quantifiable information; as a result, the writing is very lean and extra words are avoided.

A research article has the following major sections: Title Page, Abstract, Introductions, Method, Results, Discussion, References, Tables and Figures. An article summary highlights the information in the Introduction, Methods, Results, and Discussion. Before you can write such a summary, you need to read and understand the article.

Reading the Article

• Allow enough time. Plan to spend at least one half of the time you devote to this assignment to reading and understanding the article. Before you can write about research, you have to evaluate it. Before you can evaluate it, you have to understand it. Before you can understand it, you have to digest it. Before you can digest, you have to read it, thoroughly. This takes more time than most students realize.
• Scan the article first. You will get bogged down in detail if you try to read a new article from start to finish. Initially you should briefly look at each section to identify:
  • general information about the study (stated in the Abstract and Introduction)
  • the hypothesis (-es) or research questions (in the Introduction)
  • the test of the hypothesis, including the sample, variables and operational definitions, and the procedures used (in the Methods)
  • the findings (in the Results, including tables and figures)
  • how the findings were interpreted (in the Discussion).
• Read for depth. After you have highlighted the question, hypothesis, findings, and interpretations, go back to the article to read about each area in more detail. Now you should expect to read each section more than once. Expect not to fully understand the article the first time. You will have to read it more than twice before you can talk about it in your own words.

Remember that you are digesting information, not swallowing it whole. If an idea is relevant to your topic, you should be able to summarize it in your own words. If you can’t, you probably don’t understand it.

Article Conditions:

• Must be from a peer reviewed source
  • American Chemical Society and Royal Society of Chemistry are two of the biggest publishers
• Cannot be more than 50 years old
• Must be a chemistry research article (not a review article)
• Must be related to your approved individual proposal topic

Article Critical Reflection Questions

Bibliographic Information:

Article Title: Spectrophotometric Determination of Vitamin C in Pharmaceutical Preparations using Ammonium Metavanadate.

Journal: Asian Journal of Research in Chemistry

Year: 2017   Volume: 10, Issue 3    Page Numbers: 341-344

Other Identifying information if not a journal:

How did you locate this article?

I found this article by logging onto the library database website. I clicked on “New search” and typed “Determination of vitamin C by titration” and I didn’t find anything I was interested in. So, I typed “Determination of vitamin C by spectrophotometry” and refined my search from newest to oldest, peer-reviewed, and articles only. This article was the third up out of 10,333 search results.

Summary:

• In 100 to 150 words summarize the main idea of the paper in laymen terms (non-scientist). Include your word count at the end of the summary.

The aim of this experiment was to test the Spectrophotometric method for measuring the concentration of vitamin C in pharmaceutical products such as Orange peel, Alma squash and Astymin C in order to compare the values obtained to the values on the manufacturer’s label. A Spectrophotometer is an instrument that passes light through a solution and measures how much light it has absorbed (Absorbance, A), but there has to be a color gradient based on the concentration of vitamin C. To accomplish this, ammonium metavanadate was added to the vitamin C, forming a green color which was bolder with increased vitamin C concentration. Using portions of known vitamin C concentration and getting their absorbances, a Beer’s law plot of Absorbance vs Concentration (μg/cm³). Unknown concentrations can be found using the equation of the trendline, of this graph: Absorbance, y = Slope, m (Concentration, x) + y-intercept, C.

(147 words)

Procedures:

• In your own words, describe the specifics of what this study involved. What where the samples? How were they grouped? What analysis did they complete? Under what conditions? For how long? What was measured? What was being compared?

In this experiment, each of the pharmaceutical products such as Orange peel, Alma squash and Astymin C were prepared differently based on their stock solution, to 1000ppm. For the Orange peel power, they weighed out 10 grams of the powder, diluted to 250 mL of distilled water, boiled for 5 hrs., filtered using Whatman 41 paper, and 5mL was used. For the Amla squash, 10 mL of stock was diluted to 100 mL and 10 mL was used. Lastly for the Astymin C drops, 0.1 mL of stock was diluted to 100 mL and 1 mL was used. Their recommended procedure was to use 1 mL of a solution of 1000 ppm vitamin C with 1 mL of a 0.5 % w/v ammonium metavanadate (prepared by dissolving 0.5g of ammonium metavanadate in 100 mL of distilled water) made to a 25 mL solution using distilled water. This solution was in the 5.0-6.0 pH range.

The maximum wavelength was 395 nm and this was gotten using an absorption spectra of the complex against a blank. It was found that the complex and color was unstable past four hours, however, the color showed instantly. A Beer’s law plot of Absorbance vs Concentration (μg/cm³) was done for known concentrations of vitamin C, and then used to find the concentration of the Unknowns using the equation of the trendline, of this graph: Absorbance, y = Slope, m (Concentration, x) + y-intercept, C. There was no table showing the data values for the known compounds. The results of this method was tested using the pH metric method to validate the results, but this was done only with the Orange squash sample.

For the tools, a. Boush and Lomb spectronic-20 was used with 1cm matched glass cell. Potassium chromate in KOH solution and potassium permanganate in sulphuric acid solution was used to calibrate the spectrophotometer, using an absorption spectra. This was not explained in detail. The pH meter was also calibrated, done pH 4.0, 7.0 and 9.2 buffer solutions.

Findings:

• In your own words discuss the major findings and results. How useful or significant is this (what did the author(s) say about it?)

For the calibration curve the line was y= 0.009x + 0.014 with an R² value of 0.9951. Because the R² value is strong, the correlation is also strong.

For the Orange peel powder, the Spectrophotometric method gave 52.00 ± 4.62 μg/cm³ and the pH metric method 49.00 ± 3.35 μg/cm³ which is very close. There was no data on the manufacturer’s concentration.

For the Amlasquash (Nutri value) the Spectrophotometric method gave 63.33 ±5.76 μg/cm³ with a factory value of 65 μg/cm³, which is also close.

For Astymin C drops the Spectrophotometric value was 66.66 ± 5.77 μg/cm³ and the factory value was 70 μg/cm³ . No data for pH method.

The precision and accuracy of the method was tested by doing 8 replicate sampeles of each solution of 200.0 μg of vitamin C. The average was .94±0.028 at 95% confidence level. The standard deviation was 0.0394 and the variance was 0.0016.

Personal comments:

• Give your reaction to the study? Such as: What did you learn from the study? How might you apply the results in a future application? Explain how this study might relate to the lab, lab topic, and/or your project. Do you think this is scientifically valid? You must defend your answer.

This was an adaptation of what was learned in class. I believe it was necessary to do both pH metric and spectrophotometric methods to test the result.

Critical Reflection of a Journal Article (USE THIS AS A GUIDE –  REFERENCE THE SAME ARTICLE)

Summarizing research articles will help you to develop your critical thinking skills and your ability to express yourself in the written form. A research article is written to get across a lot of information quickly to a reader. Reading such articles can be tedious and sometimes frustrating unless you are familiar with scientific writing and the reasons for this style. Research articles are highly structured to make information easy to find. Unlike literary writing, scientific writing emphasizes quantifiable information; as a result, the writing is very lean and extra words are avoided.

A research article has the following major sections: Title Page, Abstract, Introductions, Method, Results, Discussion, References, Tables and Figures. An article summary highlights the information in the Introduction, Methods, Results, and Discussion. Before you can write such a summary, you need to read and understand the article.

Reading the Article

• Allow enough time. Plan to spend at least one half of the time you devote to this assignment to reading and understanding the article. Before you can write about research, you have to evaluate it. Before you can evaluate it, you have to understand it. Before you can understand it, you have to digest it. Before you can digest, you have to read it, thoroughly. This takes more time than most students realize.
• Scan the article first. You will get bogged down in detail if you try to read a new article from start to finish. Initially you should briefly look at each section to identify:
  • general information about the study (stated in the Abstract and Introduction)
  • the hypothesis (-es) or research questions (in the Introduction)
  • the test of the hypothesis, including the sample, variables and operational definitions, and the procedures used (in the Methods)
  • the findings (in the Results, including tables and figures)
  • how the findings were interpreted (in the Discussion).
• Read for depth. After you have highlighted the question, hypothesis, findings, and interpretations, go back to the article to read about each area in more detail. Now you should expect to read each section more than once. Expect not to fully understand the article the first time. You will have to read it more than twice before you can talk about it in your own words.

Remember that you are digesting information, not swallowing it whole. If an idea is relevant to your topic, you should be able to summarize it in your own words. If you can’t, you probably don’t understand it.

Article Conditions:

• Must be from a peer reviewed source
  • American Chemical Society and Royal Society of Chemistry are two of the biggest publishers
• Cannot be more than 50 years old
• Must be a chemistry research article (not a review article)
• Must be related to your approved individual proposal topic

Article Critical Reflection Questions

Bibliographic Information:

Article Title: Spectrophotometric Determination of Vitamin C in Pharmaceutical Preparations using Ammonium Metavanadate.

Journal: Asian Journal of Research in Chemistry

Year: 2017   Volume: 10, Issue 3    Page Numbers: 341-344

Other Identifying information if not a journal:

How did you locate this article?

I found this article by logging onto the library database website. I clicked on “New search” and typed “Determination of vitamin C by titration” and I didn’t find anything I was interested in. So, I typed “Determination of vitamin C by spectrophotometry” and refined my search from newest to oldest, peer-reviewed, and articles only. This article was the third up out of 10,333 search results.

Summary:

• In 100 to 150 words summarize the main idea of the paper in laymen terms (non-scientist). Include your word count at the end of the summary.

The aim of this experiment was to test the Spectrophotometric method for measuring the concentration of vitamin C in pharmaceutical products such as Orange peel, Alma squash and Astymin C in order to compare the values obtained to the values on the manufacturer’s label. A Spectrophotometer is an instrument that passes light through a solution and measures how much light it has absorbed (Absorbance, A), but there has to be a color gradient based on the concentration of vitamin C. To accomplish this, ammonium metavanadate was added to the vitamin C, forming a green color which was bolder with increased vitamin C concentration. Using portions of known vitamin C concentration and getting their absorbances, a Beer’s law plot of Absorbance vs Concentration (μg/cm³). Unknown concentrations can be found using the equation of the trendline, of this graph: Absorbance, y = Slope, m (Concentration, x) + y-intercept, C.

(147 words)

Procedures:

• In your own words, describe the specifics of what this study involved. What where the samples? How were they grouped? What analysis did they complete? Under what conditions? For how long? What was measured? What was being compared?

In this experiment, each of the pharmaceutical products such as Orange peel, Alma squash and Astymin C were prepared differently based on their stock solution, to 1000ppm. For the Orange peel power, they weighed out 10 grams of the powder, diluted to 250 mL of distilled water, boiled for 5 hrs., filtered using Whatman 41 paper, and 5mL was used. For the Amla squash, 10 mL of stock was diluted to 100 mL and 10 mL was used. Lastly for the Astymin C drops, 0.1 mL of stock was diluted to 100 mL and 1 mL was used. Their recommended procedure was to use 1 mL of a solution of 1000 ppm vitamin C with 1 mL of a 0.5 % w/v ammonium metavanadate (prepared by dissolving 0.5g of ammonium metavanadate in 100 mL of distilled water) made to a 25 mL solution using distilled water. This solution was in the 5.0-6.0 pH range.

The maximum wavelength was 395 nm and this was gotten using an absorption spectra of the complex against a blank. It was found that the complex and color was unstable past four hours, however, the color showed instantly. A Beer’s law plot of Absorbance vs Concentration (μg/cm³) was done for known concentrations of vitamin C, and then used to find the concentration of the Unknowns using the equation of the trendline, of this graph: Absorbance, y = Slope, m (Concentration, x) + y-intercept, C. There was no table showing the data values for the known compounds. The results of this method was tested using the pH metric method to validate the results, but this was done only with the Orange squash sample.

For the tools, a. Boush and Lomb spectronic-20 was used with 1cm matched glass cell. Potassium chromate in KOH solution and potassium permanganate in sulphuric acid solution was used to calibrate the spectrophotometer, using an absorption spectra. This was not explained in detail. The pH meter was also calibrated, done pH 4.0, 7.0 and 9.2 buffer solutions.

Findings:

• In your own words discuss the major findings and results. How useful or significant is this (what did the author(s) say about it?)

For the calibration curve the line was y= 0.009x + 0.014 with an R² value of 0.9951. Because the R² value is strong, the correlation is also strong.

For the Orange peel powder, the Spectrophotometric method gave 52.00 ± 4.62 μg/cm³ and the pH metric method 49.00 ± 3.35 μg/cm³ which is very close. There was no data on the manufacturer’s concentration.

For the Amlasquash (Nutri value) the Spectrophotometric method gave 63.33 ±5.76 μg/cm³ with a factory value of 65 μg/cm³, which is also close.

For Astymin C drops the Spectrophotometric value was 66.66 ± 5.77 μg/cm³ and the factory value was 70 μg/cm³ . No data for pH method.

The precision and accuracy of the method was tested by doing 8 replicate sampeles of each solution of 200.0 μg of vitamin C. The average was .94±0.028 at 95% confidence level. The standard deviation was 0.0394 and the variance was 0.0016.

Personal comments:

• Give your reaction to the study? Such as: What did you learn from the study? How might you apply the results in a future application? Explain how this study might relate to the lab, lab topic, and/or your project. Do you think this is scientifically valid? You must defend your answer.

This was an adaptation of what was learned in class. I believe it was necessary to do both pH metric and spectrophotometric methods to test the result.