Unit 19 Assignment 3 – Practical Chemical Analysis
Explaining the function of capillary GC and HPLC components
Capillary GC
Capillary Gas Chromatography (GC) is a powerful analytical technique used in
chemical analysis. It separates and analyses compounds in complex mixtures. In
capillary GC, the stationary phase is coated on the inside of a small diameter
capillary tube. When a sample is injected into the GC system, it vaporises and
travels through the capillary column. The compounds separate based on their
interaction with the stationary phase and the carrier gas. The separated
compounds exit the column and are detected by a detector, providing valuable
information about the composition of the sample. This method allows for high
resolution and sensitivity, making it a valuable tool for identifying unknown
compounds within different samples.
(Lab Compare, n.d.)
HPLC Components
In High-Performance Liquid Chromatography (HPLC), there are several key
components that work together to separate and analyse compounds in a sample.
The main components of an HPLC system include:
Pump – the pump is responsible for pushing the liquid solvent (mobile phase) at a
constant flow rate through the system. It ensures a consistent flow of the sample
through the column for efficient separation.
Injector – the injector introduces the sample into the mobile phase stream that
flows through the column. It is crucial for delivering precise amounts of the
sample for separation.
Column – the column is the heart of the HPLC system where the separation of the
compounds occurs. It is packed with a stationary phase that interacts with the
sample components as they pass through, leading to separation based on their
chemical properties.
Detector – the detector measures the compounds as they elute from the column.
It detects and quantifies the separated compounds based on their interaction
with the detector, providing valuable data on the composition of the sample.
Column oven – the column oven controls the temperature of the column.
Maintaining a constant temperature is essential for reproductible results and
optimal separation efficiency.
Mobile phase reservoir – the reservoir holds the solvent or mobile phase used to
carry the sample through the system. It ensures a continuous supply of the
solvent for the analysis.
Data system – the data system collects and processes the signals from the
detector, converting them into a chromatogram that represents the separated
compounds. It allows for a data analysis and interpretation.
,Unit 19 Assignment 3 – Practical Chemical Analysis
By working together, these components enable precise separation, detection,
and analysis of compounds in a sample. This makes HPLC a versatile and
powerful analytical technique within various fields.
(Perkin Elmer, 2023)
Hand drawn illustrations
Two examples of the use of GC and HPLC in real-life applications
Two examples of the use of GC in real-life applications are within forensic science
and within food regulation.
Gas chromatography is commonly used within forensic science to analyse crime
scenes and the evidence that is found within them. It can be used to analyse
substances such as drugs, explosives, and accelerants that are found. Due to the
fact that this process can separate compounds, this makes drug or substance
identification much easier to determine and allows for investigators to seize
validated, accurate evidence. The peaks that are shown from the results of the
GC process are compared to known peaks from different compounds and known
standards. This is used to identify which substances are present within the
sample. Information such as substance identification can be crucial in
, Unit 19 Assignment 3 – Practical Chemical Analysis
investigations as it helps to provide evidence that can link suspects to a crime
scene or help determine the exact cause of the crime.
(Rachel Ali Rodriguez, 2023)
Gas chromatography is used in food regulation to ensure the safety and quality
of food products. It is a valuable tool for analysing the food components,
contaminants, additives, and flavours. GC helps the regulatory agencies monitor
food safety as it detects harmful substances such as pesticides, mycotoxins, and
other contaminants that may cause the consumer harm within the food samples.
Similarly to the forensic science aspect, the GC process produces a peak chart
that shows the presence of any compounds or substances that may be present
within the samples. By comparing these results to known standards and
regulations, food safety authorities can ensure that the food products that are
being tested meet the legal requirements and are safe for consumption. GC is a
crucial procedure for food regulation as it allows for the precise analysis of food
components and contaminants, helping to protect the public health and ensures
that food safety standards are met. As it is highly sensitive and accurate, it
makes the GC process an essential tool in monitoring and enforcing food
regulations to safeguard consumers from potential health risks associated with
contaminated food products.
(Drawell, 2023)
Two examples of the use of HPLC in real-life applications are the purification of
water and impurity detection in the pharmaceutical industry.
High-Performance Liquid Chromatography is used in water purification to help
analyse and detect contaminants present in water. It is an essential technique for
assessing the quality of water and ensuring that it meets safety standards for
public consumption. The detector will generate signals based on the compounds
that it finds present. These signals are analysed to identify and quantify the
contaminants that are found to be within the water sample. These results are
compared to known regulatory limits within water treatment facilities to
determine whether the water meets the quality standards or if the water has to
undergo further purification. HPLC is a crucial process when it comes to water
purification as it allows for the precise analysis of contaminants such as
pesticides, heavy metals, and organic pollutions. Upon the detection of these
contaminants, HPLC can help to quantify these substances to ensure that the
water treatment processes are effectively removing harmful contaminants and
providing safe drinking water to the public.
(Elga Veolia, 2024)
High-Performance Liquid Chromatography is also used within the pharmaceutical
industry to help detect any impurities within drug products. It helps to ensure the
quality and safety of medications by identifying and quantifying impurities that
could affect the efficacy and safety of the drugs. The detector produces signals
based on the amount of each compound that is present. These signals are then
analysed to identify the impurities and which can then determine their
concentration levels. By comparing the results to regulatory guidelines,
pharmaceutical companies can ensure that their drug products meet quality
