Elements and Performance Criteria

The range of variables relates to the unit of competency as a whole. It allows for different work environments and situations that will affect performance.
Where reference is made to industry codes of practice, and/or Australian/international standards, it is expected the latest version will be used.
All operations and analytical methods must comply with relevant standards, appropriate procedures and/or enterprise requirements.

These procedures include or have been prepared from
Australian and international standards such as -
AS ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories
ISO 9000 series Quality management and quality assurance standards
AS 2243.2 Safety in laboratories - chemical aspects
AS 2830.1 Good laboratory practice - chemical analysis
codes of practice such as GLP and GMP
material safety data sheets (MSDSs)
National Measurement Act
standard operating procedures (SOPs)
quality manuals, equipment and procedure manuals
equipment start-up, operation and shutdown procedures
calibration and maintenance schedules
data quality procedures
enterprise recording and reporting procedures
production and laboratory schedules
material, production and product specifications.

Specialised analytical instruments may include
spectrometric instruments such as
electrothermal AAS
vapour generation AAS
X-ray fluorescence XRF and diffraction XRD
nuclear magnetic resonance NMR, magnetic resonance imaging MRI
mass spectrometry MS
neutron activation analysis NAA
ICP-MS
chromatographic instruments such as-
GC-MS
GC sampling devices (for example, headspace, thermal desorption)
specialised GC detection devices (for example, ECD, FPD, NPD)
specialised GC detection devices (for example, fluorescent, diode array, electrochemical)
LC-MS, electro spray MS
GC-FTIR
electrometric instruments such as anodic stripping voltammetry
flow injection analytical equipment.

Tests requiring specialised instruments may include
trace analysis
non destructive testing
multi-analyte determination
analysis involving high sample throughput.

Instrument sub systems may include
sample introduction units, auto sampling equipment
detectors, signal conditioning units
temperature control devices such as cryostats, ovens, thermostat baths
software control/interface.

Sample preparation may include
identification of any hazards associated with the samples and/or analytical chemicals
grinding, mulling, preparation of disks, digestion, dissolving, ashing, refluxing, extraction, filtration, evaporation, flocculation, precipitation, washing, drying, centrifugation
solid-phase micro extraction
determination of, and if appropriate, removal of any contaminants or impurities
ultratrace procedures requiring high purity solvents, clean rooms, ultra clean glassware, specialised glassware.

Common analytical procedure and equipment problems may include
sample introduction blockages
incomplete atomisation of analyte
poor resolution of peaks
poor sensitivity.

Hazards may include
electric shock
biohazards such as-
microbiological organisms and agents associated with soil, air, water, blood and blood products, human or animal tissue and fluids
mycotoxins
chemicals such as-
acids for example, sulphuric, perchloric, hydrofluoric
heavy metals, pesticides
anions for example, fluoride
hydrocarbons for example, mono-aromatics
radiation (alpha, beta, gamma, X-ray, neutron)
sharps, broken glassware
aerosols from broken centrifuge tubes, pipetting
flammable liquids and gases
cryogenics such as dry ice and liquid nitrogen
fluids under pressure such as hydrogen in gas liquid chromatography, acetylene in atomic absorption spectrometry
sources of ignition
high temperature ashing processes
disturbance or interruption of services

Addressing hazards may include
use of material safety data sheets (MSDS)
labelling of samples, reagents, aliquoted samples and hazardous materials
personal protective equipment such as gloves, safety glasses, coveralls
use of fumehoods, direct extraction of vapours, gases
use of appropriate equipment such as biohazard containers, laminar flow cabinets, Class I, II and III biohazard cabinets
handling and storage of all hazardous materials and equipment in accordance with labelling, materials safety data sheets and manufacturer's instructions
minimising exposure to radiation ionising such as lasers, electromagnetic and ultraviolet radiation.

Health, safety and environment
All operations to which this unit applies are subject to stringent health, safety and environmental (HSE) requirements, which may be imposed through State or Federal legislation, and these must not be compromised at any time. Where there is an apparent conflict between performance criteria and HSE requirements, the HSE requirements take precedence.
All operations assume the potential hazardous nature of samples and require standard precautions to be applied. Users should access and apply current industry understanding of infection control issued by the National Health and Medical Research Council and State and Territory Departments of Health. All operations are performed in accordance with standard operating procedures.

The Evidence Guide describes the underpinning knowledge and skills that must be demonstrated to prove competence.
Critical aspects of competency

Competency must be demonstrated in the ability to perform consistently at the required standard. In particular, assessors should look to see that the candidate:

interprets client request, test methods and procedures accurately
can safely set up, start up and shut down equipment using enterprise procedures
assembles checks and optimises instrument sub systems
checks calibration/qualification status of equipment
prepares samples and standards appropriately
optimises procedures and equipment to suit sample/test requirements
operates equipment to obtain valid and reliable data
calculates analyte concentrations with appropriate accuracy, precision and units
recognises atypical data/results
troubleshoots common analytical procedure and equipment problems
applies theoretical knowledge to interpret data and makes relevant conclusions
records and reports data/results using enterprise procedures
maintains security, integrity and traceability of samples and documentation
follows OHS procedures and GLP.

Underpinning knowledge

Competency includes the ability to apply and explain:

principles and concepts related to instrument operation, material preparation and testing, such as-
mechanisms for absorption/emission
distinction between SIM and TIC mode in GC-MS
sequence of steps required for successful ASV
function of key components and sub system of the instrument
handling of hazardous chemicals and samples and/or the fragile/labile nature of biological material
sample preparation procedures
effects on outputs and results of modifying instrumental variables
procedures for optimising instrument performance
basic procedure and equipment troubleshooting techniques
preparation and use of calibration charts and/or standards
calculation steps to give results in appropriate units and precision
basic equipment maintenance procedures
enterprise and/or legal traceability requirements
relevant health, safety and environment requirements.

Assessment context and methods
This unit of competency is to be assessed in the workplace or simulated workplace environment.

The following assessment methods are suggested:

review of test data/results obtained by the candidate over time to ensure accuracy, consistency and timeliness of results
inspection of test records and enterprise documentation completed by the candidate
observation of candidate using specialised instruments to measure analytes
feedback from clients, peers and supervisors
oral or written questioning of relevant chemical principles, concepts, analytical techniques and enterprise procedures.
In all cases, practical assessment should be supported by questions to assess underpinning knowledge and those aspects of competency which are difficult to assess directly. Questioning techniques should suit the language and literacy levels of the candidate.

Interdependent assessment of unit

This unit of competency may be assessed with:

PMLDTA500B Analyse data and report results.

Resource Implications

Resources may include:

standard laboratory with specialised analytical instruments
laboratory reagents and equipment
standard operating procedures (SOPs) and test methods.

This competency in practice
If oysters and other shellfish accumulate significant levels of heavy metals, they can represent a public health risk when consumed by humans. Analysis of heavy metal residues requires digestion of the sample in a concentrated acid, typically nitric. The digest is diluted in ultra pure water and analysed by standard addition and electrothermal AAS using a phosphate modifier to reduce lead volatility. The technician must pay careful attention to the digestion process and to the widely varying absorbances that will result from oysters of having accumulated different concentrations of residue.
Electrothermal atomic absorption (AA) spectrophotometers are one of the more common instruments for the analysis of microgram/litre levels of metals. Setting up the instrument requires more skill and care than a normal flame AAS instrument. Firstly, the technician must check the graphite tube for wear, replace it if necessary, and re-align it. The auto sampler delivery tube must also be checked for its alignment so that delivery of the micro litre aliquots of solution is accurate and precise. The technician must also make the standards with great attention to avoid contamination from glassware and reagents.
The physical and mechanical properties of metal alloys are crucially dependent on their composition. Therefore, the composition of alloys must be checked carefully. While acid dissolution and analysis by flame AAS or ICP emission spectroscopy is possible, one of the most common techniques used is X-ray fluorescence because it does not have the same demanding sample preparation requirements. XRF samples, after polishing to remove any surface defects, can be analysed directly against reference standards of the same alloy. Control of instrument variables is critical in obtaining accurate results. This requires the technician to carefully optimise a number of components within the overall instrument before conducting the analysis.
An insurance company contracted a consulting laboratory to conduct tests on an accelerant residue that may have been used in a recent arson attack on a local school building. The residue was run through a column chromatograph and compared with reference standards (such as petrol, kerosene, 50% mixtures, evaporated petrol) to establish the identity of the sample. Confirmation of these results was obtained by using a GC-MS instrument to establish the identity of the sample beyond reasonable doubt along with additional tests for heavy metals such as lead.

The seven key competencies represent generic skills considered for effective work participation. The bracketed numbering against each of the key competencies indicates the performance level required in this unit. These are stand-alone levels and do not correspond to levels in the Australian Qualifications Framework (AQF).
Level (1) represents the competence to undertake tasks effectively
Level (2) represents the competence to manage tasks
Level (3) represents the competence to use concepts for evaluating and reshaping tasks.
Communicating ideas and information
(2)

Collecting analysing and organising information
(2)

Planning and organising activities
(2)

Working with others and in teams
(2)

Using mathematical ideas and techniques
(2)

Solving problems
(3)

Using technology
(3)