Analysing the Iron Content in Different Vegetables

Analysing the Iron Content in Different Vegetables[pic 1][pic 2]

Introduction

Background

Iron is a mineral that holds many important roles throughout the human body. It is an essential nutrient because it is a vital component of haemoglobin, the substance in red blood cells that carry oxygen from your lungs to transport it throughout the body. Iron is also involved in the conversion of blood sugar to energy. Known as metabolic energy, it is crucial for everyone, especially athletes, since it allows muscles to work at their optimum level.

According to the World Health Organization [1], iron deficiency is the most common mineral deficiency in the world. Symptoms of not having enough iron can lead to fatigue, lack of stamina, and decreased ability to concentrate at an effective level.

In the popular television show Popeye, it is seen that he consumes a large amount of canned spinach because of the high amount of iron that was believed to be found in it. Is this the correct food sample to be representing to the audience, or are there other vegetables that contest spinach to also be rich in iron content? An experiment using colorimetric analysis will be conducted to determine the answer to this research question.

Aim

The aim of this extended experimental investigation is to analyse the iron content in a variety of vegetables, specifically spinach, asparagus and bok choy. Asparagus was chosen because it is the second most iron rich vegetable after spinach [2].

This report is based on the experiment we undertook to achieve our goal. It explored the process of colorimetric analysis to determine and observe the iron content in different vegetables through colour absorbency.

In this analysis the iron present in a food sample is extracted to form a solution containing Fe3+ ions. To make the presence of these ions visible, thiocyanate ions (SNC-) are added. These react with Fe3+ ions to form a blood-red complex:

Fe3+(aq) + SCN-(aq) → [FeSCN]2+(aq)

By comparing the intensity of the colour of this solution with the colours of a series of standard solutions, with known Fe3+ concentrations, the concentration of iron in the tablet or food sample may be determined. This technique is called colourimetry [3].

Hypothesis

If spinach contains the highest amount of iron, then the colour absorbance would be greater than the other vegetables because the absorbance is an indicator of how many FE^+ ions.

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Procedure

Preparation of standardized solutions: