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 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
AS 2243.2 Safety in laboratories - chemical aspects
AS 2830.1 Good laboratory practice - chemical analysis
AS 2162.1 General - volumetric glassware
AS 2134.1 Flame atomic absorption spectroscopy
Codes of Practice, such as GMP and GLP
material safety data sheets (MSDSs)
National Measurement Act
standard operating procedures (SOPs)
quality manuals, equipment and procedure manuals
equipment startup, 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.

Test requirements may include
specification of concentration and limits of analytes
time and cost limitations
use of specific standards, such as AS, APHA, AOAC, ASTM, US EPA.

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

Quantification techniques may include
matrix matched standards
standard additions
international standards.

Analytical techniques may include
spectrometric techniques, such as ICP-OES, ICP-MS
chromatographic techniques, such as GC-MS, Ion Chromatography
electrometric techniques, such as ion selective electrodes, voltammetry (polarography), anodic stripping voltammetry
electrophoretic techniques, such as capillary electrophoresis.

Typical analytes and samples requiring complex tests may involve
contaminants in food, such as heavy metals, afflotoxins
trace level (microgram and nanogram/litre) analytes
forensic testing, drug testing in body tissues and fluids
multiple analytes, such as organochlorines, polyaromatic hydrocarbons
environmental contaminants in water, soil and air (such as pesticides)
sludge, wastewater, sewage
samples with matrix interferences.
Validation checks may include recovery checks and use of standard/certified samples.

Common analytical procedure and equipment problems may include
matrix interference
spectral interference
problems associated with the physical state of the analyte, such as blockages, viscosity changing flow rates to instruments.

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 (nuclear, lasers, UV)
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
use of 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.

Tests for completeness of sample preparation may include
visual inspection for colour, solids
odour
pH, conductivity
chemical tests for interferents, such as precipitation, colour forming
basic screening instrumental tests, such as IR, UV/VIS, and GC.

Modifiers may include
ionisation suppressants, such as Caesium for Ca, Na, K in AAS
ionic strength and pH buffers, such as TISAB for fluoride in ISE
releasing agents, such as Lanthanum and Strontium for Ca in AAS
volatility suppressants, such as phosphate for Pb in electrothermal AAS.

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 potentially 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
checks calibration/qualification status of equipment
prepares samples and standards appropriately
optimises procedures and equipment to suit sample/test requirements
maintains close attention to measurement procedures, accuracy and precision during lengthy complex tests
calculates analyte concentrations with appropriate accuracy, precision and units
recognises atypical data/results
troubleshoots common analytical procedure and equipment problems
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 underpinning the analysis, such as-
effects of interferents with analyte behaviour, such as ionisation, complexation, precipitation, masking, association
quantification methods, such as internal standards, standard additions, Gran's Plot, recovery checks
chemical, physical treatments to minimise interferences
function of key components of equipment
effects of modifying instrumental variables on outputs and results
handling of hazardous chemicals and samples and/or the fragile/labile nature of biological material
sample preparation procedures
preparation and use of calibration charts and/or standards
calculation steps to give results in appropriate units and precision
enterprise and/or legal traceability requirements
basic procedure and equipment troubleshooting techniques
basic equipment maintenance procedures
relevant health, safety and environment requirements.

Specific industry

Additional knowledge requirements may apply for different industry sectors. For example:

nature of specific sample matrices
special needs for sample treatment/pre-treatment
industry specific instrumentation.

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 workplace documentation completed by the candidate
observation of candidate conducting a range of complex tests to measure chemical properties of materials
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:

PMLDATA500B Analyse data and report results.

Resource implications

Resources may include:

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

This competency in practice
The analysis of a soil sample for nutrient profiles requires a complex procedure for simplifying the soil matrix and then performing multiple analyses on the sample in order to obtain data on both macro and micro soil nutrients. To determine the chemical suitability of a particular soil for agricultural activity, a detailed analysis is required of macronutrients, such as nitrate, phosphate and potassium as well as micronutrients, such as metals (including Cu, Se Mo, Fe) and sulphate.
A technician is given a composite soil sample from a client and uses the standard techniques of riffling and coning and quartering to obtain representative sub samples for laboratory analysis. The technician then removes the soil matrix by one of several methods depending on the type of nutrient analysis being performed.
For soil micronutrients, such as trace metals, they dry the sample (to remove moisture and obtain the dry weight); then wet ash it with concentrated sulphuric acid (to remove carbonaceous components); and finally resuspend it in dilute nitric acid. Once the technician is satisfied that the matrix has been simplified sufficiently, they then use an inductively coupled plasma spectrophotometer to ascertain the concentration of trace metals in the soil.
The analysis for macronutrients, such as phosphate, is performed in several ways due to the enormously variable processes involved in weathering of parent material into soil. One common macronutrient test is for leachable phosphate - which involves extraction of labile phosphate from the soil matrix. In this case, the technician uses the Olsen method. They remove the analyte from the complex soil matrix by extracting it with hydrogen carbonate solution and quantify the liberated analyte using visible spectrophotometry.

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)