Exp 1.docx

UNIVERSITI KUALA LUMPUR MALAYSIAN INSTITUTE OF CHEMICAL & BIOENGINEERING TECHNOLOGY

LABORATORY TECHNICAL REPORT SUBMISSION FORM

To: Dr. Khairul Faizal Bin Pa’ee

Code Subject: CFB 20203

From:

Student ID. No.:

-Nuryuhanis Bt. Yazid

-55218116016

-Qurratu Aini Firdaus Bt. Mohd Raffie

-55218116146

-Nurul Asnaida Bt. Abu Hamdan

-55218116191

No. of Group: E

Date of Experiment: 26.7.2018

Title of Experiment: Experiment 1 - Safety in the Laboratory and Handling of Apparatus and Equipments Received by:

Date of Submission: 1.8.2018

Note: Late submission will not be accepted.

*To be filled by the marker* VERY POOR 1

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2.0 PROCEDURES (TOTAL: 5%) 1.Methodology is presented in suitable and understandable flowchart.

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3.0 RESULTS (TOTAL: 10%) 1.Data are presented as deemed suitable with complete label and units in tables and/or graphs.

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CRITERIA

1.0 ABSTRACT & OBJECTIVES (HALF PAGE ONLY) (TOTAL: 10%) 1. State the summary to the experiment conducted. 2. State the objectives of the experiment (point form)

4.0 DISCUSSIONS (MAXIMUM 1 PAGE) (TOTAL: 3 15%) 1. Explanations of the referred tables and/or Lab Technical graphs are presented after it. 2. Discuss on the findings and relations to the theory and objective of experiment.

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4.0 DISCUSSIONS (MAXIMUM 1 PAGE) (TOTAL: 15%) 1. Explanations of the referred tables and/or graphs are presented after it.

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5.0 CONCLUSIONS (TOTAL: 5%) 2. Discuss on the findings and relations to the 1. Summary of the results to relate the findings or theory and objective of experiment. results with the theory applicable to the experiment.

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6.0 REFERENCES (TOTAL: 5%)

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1. Minimum of 4 references.

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Abstract & Objective(s): It is important to practice the safety in laboratory and on how to handle the apparatus and equipment that are used in the laboratory in order to avoid accidents from happened. Every person’s in the laboratory need to be aware of the principles of laboratory safety to ensure that the experiments that will be conducted going to be run smoothly. Care should be taken into account when experiments are being conducted to avoid any harm to be done. Handling the apparatus and equipment such as micropipetter correctly are important when doing experiments. Micropipette is a common equipment in the laboratory that function to measure and transfer a small volume of liquids. Micropipette comes in a variety of types and sizes based on the volume that has been set for it. The accuracy and precision for a micropipette can be done by calculate the percentage error and mean deviation based on the collected data from the conducted experiments.

Objectives : 1. To learn on how to use and check the calibration of micropipette correctly. 2. To learn the proper handling of micropipette. 3. To determine the accuracy and precision of measurements taken using micropipette. 4. To learn how to pick the suitable micropipette for a particular volume.

Methodology: Using a suitable flowchart, state the steps involve in this lab work. Four colours solution were prepared. Each 1.5ml tubes were labelled with A, B, C, E, and F.

The tube filled with total solutions was homogenized, then it was weighed and recorded.

The tubes were filled with different solutions until the total become 10μl using micropipettor

Each tube was weighed and recorded.

The solution was taken by setting the micropipettor and suitable tips was used, push the plunger down to the first detent position. Incorrect volume of liquid will be delivered if the second detention were pressed.

To check the measurements were accurate, the pipette was set to 10μl and carefully withdraw the solution from each tube.

The same procedure of exercise practical was repeated but differently using large volume micropipettor of 1000µl.

Result/ Discussion:

Table 1 : Small Volume Micropipettor Exercise Tube

A

B

C

Initial weight (g)

0.943

0.944

0.950

Final weight (g)

0.953

0.956

0.960

Actual Value

0.010

0.012

0.010

0.011

Mean

10

Percentage Error (%)

Table 2 : Large Volume Micropipettor Exercise Tube

E

F

Initial weight (g)

0.738

0.935

Final weight (g)

1.923

1.931

Actual Value

1.185

0.996 1.091

Mean

9.1

Percentage Error (%)

Calculation percentage error for small volume : %error = =

𝐴𝑣𝑒𝑟𝑎𝑔𝑒−0.01 0.01

0.011−0.01 0.01

× 100

× 100

= 10% Calculation percentage error for large volume : %error = =

𝐴𝑣𝑒𝑟𝑎𝑔𝑒−1.0 1.0

1.091−1.0 1.0

× 100

× 100

= 9.1%

Calculation mean deviation for small volume : Mean Deviation = =

∑| X− µ | 𝑁

|( 0.010−0.011)+(0.012−0.011)+(0.010−0.011 )| 3

= 0.33 × 10-3 Calculation mean deviation for small volume : Mean Deviation = =

∑| X− µ | 𝑁

|( 1.185−1.091)+(0.996−1.091)|

= 0.0945

2

Micropipettes are the standard laboratory equipment used to measure and transfer small volumes of liquids. Micropipettes come in a variety types and sizes designed for a particular range of volume. There are three types of micropipette that have been used in this experiment which are 10µl, 100µl and 1000µl micropipette. The purposes of this experiment are to learn how to use and check the calibration of micropipette properly, learn the proper handling of micropipette, determine the accuracy and precision of measurements taken and learn how to pick the suitable micropipette for a particular volume. In this experiment, it is important to calculate the percentage error and the mean deviation based on the collected data. The experiment was began with the preparation of four different colored solutions that is visible. Three 1.5ml reaction tubes were labeled with A,B and C for small volume micropipettor exercise and for large volume, the tubes were labeled with E and F. The initial and final weight of those reaction tubes were measured in this experiment to calculate the percentage error and mean deviation. From the result obtained from Table 1 and Table 2, it can be determine how precise and accurate the result when using a particular micropipette. Accuracy is a measure of how close a measured value is to the accepted or “true” value while precision measures the closeness of a set of values obtained from identical measurements of the same quantity. To determine the accuracy and precision of the reading, the percentage error and mean deviation were calculated. From Table 1, the percentage error and mean deviation are 10% and 0.33 × 10-3 approximately. Thus, from Table 2, the percentage error and mean deviation are 9.1% and 0.0945 approximately. So, it can be conclude that the value obtained from large volume micropipettor exercise is more accurate compared to small volume exercise since the percentage error is smaller. While the value obtained from small volume micropipettor exercise is more precise compared to large volume since the mean deviation is smaller. There are few possible errors that can occur in this experiment such as systematic error and random error that can caused inaccurate reading. In this experiment, students are able to use and check the calibration of micropipette and learn the proper handling when using micropipette. The accuracy and precision can be determined by calculating the percentage error and mean deviation. In this experiment, students must know how to pick a suitable micropipette to order to obtain an accurate and precise result and gives a small

percentage error.

Conclusion: In conclusion, different scale of micropipettors has different volume to be measured. In this experiment, the large scale of micropipettor has the higher accuracy than the small micropipettor. This is because pipetting the small amount accurately is not easy and will likely contribute greatly to the statistical error in the result. Otherwise, the small amount will give the higher precision rather than the large micropipettor with a small number of standard deviation. The possible errors had been detected during the experiment. To overcome the errors, a good handling must be done during using the micropipettors. Other than that, the micropipettors need to be serviced every 6 to 12 month including re-calibrate the pippet. So that, the micropipettor can work effectively and give a accurate and precise results.

Study question: 1. Which of the two pipettors that you used was the more accurate? Explain. a. Based on the errors of each pipettors, it showed that the 10µl has higher percent error and the 1000µl pipettor has the lower percent error. It can be indicate that the 1000µl is more accurate than 10µl pipettor. This is because the smaller percent error indicated the higher accuracy.

2. Which of the two pipettors that you used was the more precise? Explain. a. Precision is the closeness of the set values obtained from identical measurements of the same quantity. It is related to the standard deviation of the measurements. So, the lower standard deviation means the more precise the equipment. In this experiment, 10µl pipettor has a lower standard deviation rather than 1000µl pipettor. So, it can be concluded that 10µl pipettor is more precise than 1000µl pipettor.

3. What are the take-home messages from this exercise? Give three specific things that you learned from this lab.

a. The important thing is to handle the micropipettors carefully during withdraw the solution from the 1.5ml tubes, because of the bubble inside. Second, we need to use a suitable micropipettors according the volume that we need to measure because there might be an error if we choose the wrong micropipettor. Lastly, Wrong handling technique or careless during using the micropipettors will be affected the result of whole experiment.

4. Without checking the accuracy of the given pipettor, would you predict that it is better to use a 10µl or 1000µl pipettor to pipet 10µl? Why? a. It is better to use 10µl micropipettor to pipet 10µl because it is within the range of 10µl.

5. How do you make 200mL of .01 M solution of the substance that has a molecular weight of 121.1g/mol? a. 0.1 M = mol/0.2L Mol = 0.02mol Mass of substance = 121.1 g/mol * 0.02mol Mass of substance = 2.422 g

6. If you take 10mL of the solution from question 5, add 90mL of water, and then take 5mL of the mixture and bring it to 25mL, what will be concentration of the final solution in molars, milimolars and micromolars? a. 10ml (0.1 M) + 90ml = 100ml mixture of M (10ml/100ml)*0.1M = 0.001M 5ml (0.01M) + 20ml = 25ml of M (5ml/25ml) * 0.01M = 0.002 M In milimolars = 2 mM In micromolars = 2000 µM

References : 

29 CFR 1910 - OCCUPATIONAL SAFETY AND HEALTH STANDARDS. (n.d.). Retrieved on July 28, 2018

from https://www.gpo.gov/fdsys/granule/CFR-2013-title29-

vol5/CFR-2013-title29-vol5-part1910. 

Expt

1.

Pipetting

TA's

notes.

(n.d.).

Retrieved

on

July

28,

2018

from

http://cellbio7.mcb2225.uconn.edu/MCB_2225/Expt_1._Pipetting_TAs_notes.html 

Handling

Laboratory

Equipment.

Retrieved

on

July

30,

2018

on

July

30,

2018

July

28,

2018

from:

fromhttp://www2.bakersfieldcollege.edu 

Working

with

Lab

Equipment.

Retrieved

fromhttp://www.ncbi.mlm.nih.gov/books/NBK55884 

Definition

of

Micropippet.

(2018).

Retrieved

http://www.streetdirectory.com/travel_guide/119290/science/what_are_micropipettes.html 

Using a micropippet. (July 25, 2018). Retrieved July 28, 2018 from: https://di.uq.edu.au/communityand-alumni/sparq-ed/sparq-ed-services/using-micropipette