Digestion Of Hair Lab Report
3.0 Introduction
The methodology involves five main steps; the collection of hair samples, the distribution of questionnaires, the washing of samples, the digestion of the samples, and the analysis of metal contents in the hair.
3.1 Materials and reagents used during the experiment
The apparatus and chemicals that were used in the previously mentioned experimental steps are summarised in table 3.0.
Steps
Materials
Reagents
Collection of hair samples 1. Stainless Steel Scissors
2. Plastic bags
3. Gloves 1. Hot water
2. Ethanol
Washing the hair samples 1. Forceps
2. 100 ml beakers
3. Electronic weighing balance
4. Magnetic stirrer
5. Magnets
6. Filter paper 1. Diethyl Ether
2. Acetone
3. Deionised water
4. pH 6 Shampoo
Digestion of hair …show more content…
The hair has been cut a couple of millimetres from the scalp, since the portion of hair closer to the scalp demonstrates the recent activity of a person (Watts, 2000).
The collected sample was then stored in a labelled, tightly-closed plastic bag. After cutting the hair of a participant, the scissors were wiped with alcohol, before proceeding to the next contributor. The scissors have to be sterilised before and after cutting the hair of each participant, in order to prevent external contamination from any chemical residues that might be present on them.
3.3 Distribution of questionnaires
The participants were each asked to fill a questionnaire that has been prepared specifically for this research. Some participants preferred to fill the questionnaire before sampling, some chose to do so after sampling, while a few others were orally asked the questions while sampling was been carried out. It was mandatory that each questionnaire was filled in my presence, so that no important questions were misunderstood or left unanswered.
A sample of the questionnaire can be seen in the …show more content…
3.4 Digestion of hair samples
About 0.5g of hair was weighed using an electronic balance, and the exact mass was recorded. The hair was then transferred to a 50cm3 conical flask, to which 10ml of concentrated nitric acid (69-72%) was added. The solution was then stirred and heated on a hot plate, for about 1 hour, until the hair has dissolved, and a dark brown solution was obtained. The solution was then left to cool, and then was filtered using a fluted filter paper, into a 50ml volumetric flask. The filtrate was then made up to the 50 ml mark, using deionised water. An acidic medium helps to stabilise the elements in solution (Puchyr, 1998). Check this paper to explain about this method of digestion.
Preparation of hair for measurement of elements by Inductively Coupled. Plasma-Mass Spectrometry (lCP-MS) Puchyr RF, Bass DA, Gajewski R, Calvin M, Marquardt W, Urek K, Druyan ME, Quig D (1998)
Lastly, the 25ml of digested hair solution was transferred to a clean acid-washed polyethylene bottle and stored in a refrigerator at about 5oC until being used for
The methodology involves five main steps; the collection of hair samples, the distribution of questionnaires, the washing of samples, the digestion of the samples, and the analysis of metal contents in the hair.
3.1 Materials and reagents used during the experiment
The apparatus and chemicals that were used in the previously mentioned experimental steps are summarised in table 3.0.
Steps
Materials
Reagents
Collection of hair samples 1. Stainless Steel Scissors
2. Plastic bags
3. Gloves 1. Hot water
2. Ethanol
Washing the hair samples 1. Forceps
2. 100 ml beakers
3. Electronic weighing balance
4. Magnetic stirrer
5. Magnets
6. Filter paper 1. Diethyl Ether
2. Acetone
3. Deionised water
4. pH 6 Shampoo
Digestion of hair …show more content…
The hair has been cut a couple of millimetres from the scalp, since the portion of hair closer to the scalp demonstrates the recent activity of a person (Watts, 2000).
The collected sample was then stored in a labelled, tightly-closed plastic bag. After cutting the hair of a participant, the scissors were wiped with alcohol, before proceeding to the next contributor. The scissors have to be sterilised before and after cutting the hair of each participant, in order to prevent external contamination from any chemical residues that might be present on them.
3.3 Distribution of questionnaires
The participants were each asked to fill a questionnaire that has been prepared specifically for this research. Some participants preferred to fill the questionnaire before sampling, some chose to do so after sampling, while a few others were orally asked the questions while sampling was been carried out. It was mandatory that each questionnaire was filled in my presence, so that no important questions were misunderstood or left unanswered.
A sample of the questionnaire can be seen in the …show more content…
3.4 Digestion of hair samples
About 0.5g of hair was weighed using an electronic balance, and the exact mass was recorded. The hair was then transferred to a 50cm3 conical flask, to which 10ml of concentrated nitric acid (69-72%) was added. The solution was then stirred and heated on a hot plate, for about 1 hour, until the hair has dissolved, and a dark brown solution was obtained. The solution was then left to cool, and then was filtered using a fluted filter paper, into a 50ml volumetric flask. The filtrate was then made up to the 50 ml mark, using deionised water. An acidic medium helps to stabilise the elements in solution (Puchyr, 1998). Check this paper to explain about this method of digestion.
Preparation of hair for measurement of elements by Inductively Coupled. Plasma-Mass Spectrometry (lCP-MS) Puchyr RF, Bass DA, Gajewski R, Calvin M, Marquardt W, Urek K, Druyan ME, Quig D (1998)
Lastly, the 25ml of digested hair solution was transferred to a clean acid-washed polyethylene bottle and stored in a refrigerator at about 5oC until being used for