The Evidence Guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Overview of assessment

Critical aspects for assessment and evidence required to demonstrate competency in this unit

Assessors should ensure that candidates can:

interpret client requests, test methods and procedures accurately

select, operate and maintain sample introduction and detector sub-systems

install ICP instrument sub-systems such as torch, nebuliser and spray chamber

safely set up, start up and shut down instrument using enterprise procedures

prepare samples and calibration standards in accordance with test method

check calibration/qualification status of equipment

optimise instrument sub-systems and procedures and equipment to suit sample/test requirements

operate equipment to obtain valid and reliable data

use software to identify analytes and calculate concentrations with appropriate accuracy, precision and units

recognise atypical data/results

troubleshoot common analytical procedure and equipment problems

record and report data/results using enterprise procedures

maintain security, integrity and traceability of samples and documentation

follow OHS procedures and principles of GLP.

Context of and specific resources for assessment

This unit of competency is to be assessed in the workplace or simulated workplace environment.

This unit of competency may be assessed with:

MSL976003A Evaluate and select appropriate test methods and procedures

MSL977003A Contribute to the validation of test methods

MSL977004A Develop or adapt analyses and procedures.

Resources may include:

laboratory with specialised analytical instruments

laboratory reagents and equipment

SOPs and test methods.

Method of assessment

The following assessment methods are suggested:

review of test data/results/calibration graphs obtained by the candidate over time to ensure accuracy, validity, precision and timeliness of results

inspection of results and technical records (e.g. maintenance schedules and quality control logbooks) completed by the candidate

observation of candidate using ICP instruments to measure analytes

feedback from clients, peers and supervisors

oral or written questioning of relevant ICP spectroscopy concepts, chemical principles underpinning sample preparation and separation of species, instrument design and optimisation, 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.

Where applicable, reasonable adjustment must be made to work environments and training situations to accommodate ethnicity, age, gender, demographics and disability.

Access must be provided to appropriate learning and/or assessment support when required.

The language, literacy and numeracy demands of assessment should not be greater than those required to undertake the unit of competency in a work like environment.

This competency in practice

Industry representatives have provided the case studies below to illustrate the practical application of this unit of competency and to show its relevance in a workplace setting.

Food processing

A technician is analysing trace metals in red wine. He/she knows from experience that the ethanol in the wine will extinguish the torch even under standard operating conditions. The technician has four possible remedies:

1. Dilute the sample solution

2. Boil the ethanol off

3. Adjust the torch operating conditions

4. Change the sample introduction equipment.

He/she considers factors such as the number of samples to be analysed and the likely analyte concentrations and searches the literature for recommended remedial actions. The technician decides to start by increasing the torch power from 1.0 to 1.3 KW and tuning the gas flow rates through the torch until the plasma is stable with normal sample introduction.

Environmental testing (1)

A technician receives a series of stream water samples from a client to test for elemental arsenic (As). The client advises the laboratory that they have acidified the samples as per the standard method to preserve the integrity of the sample during transit. Assuming that the client has used HNO3 to bring the pH of the samples down to 1, the technician proceeds with the ICP-MS analysis. However, the technician soon realises that the client has used HCl because there is overwhelming interference between 40Ar35Cl+ and 75As+. The clean up takes a considerable time and to prevent a recurrence of the problem, the laboratory now conducts rapid tests for chlorides in all water samples before ICP-MS analysis.

Environmental testing (2)

A technician receives a telephone call from a client requesting more information about the laboratory's ability to provide ICP-AES multi-element analysis of dry plant material as listed on the company website. The technician explains how the laboratory uses a dry ash method and requires about 500-1000 mg of sample. The technician briefly outlines how the samples are ashed in a silica crucible that is covered to prevent any contamination. The ash is then equilibrated with 5mL of 20% HCl at room temperature for 30 minutes before having 5mL of deionised water added, gently swirled and then allowed to settle for three hours. The solution is then decanted into 15mL plastic disposable tubes for direct determination by ICP-AES. The client mentions that they are particularly interested in the presence of Fe, Al and Cr and the technician notes that in this case, the laboratory usually refluxes the ash in 20% HCl to improve the recovery of these elements. The technician also advises the client that the laboratory reports elemental determinations as ppm on a weight element/dry sample weight basis and that ICP values are expressed on an atomic weight basis, not as any other molecular species.

Required skills

Required skills include:

establishing client needs for routine and non-routine samples

interpreting client requests, test methods and procedures accurately

selecting, adapting and modifying standard test methods for unknown samples

preparing samples and standards, optimising procedures and equipment to suit sample/test requirements

setting up, starting up and shutting down equipment

checking the calibration/qualification status of equipment

selecting, configuring, checking and optimising instrument sub-systems

performing routine instrument maintenance and replacement of consumables

obtaining valid and reliable data

calculating analyte concentrations with appropriate accuracy, precision, uncertainty and units

recognising atypical data/results and troubleshooting common analytical procedure and equipment problems

recording and reporting data/results using enterprise procedures

maintaining security, integrity and traceability of samples and documentation

assessing risks, applying specified control measures and working safely

minimising waste and ensuring safe collection and disposal of waste materials

applying relevant principles of good laboratory practice (GLP) procedures

maintaining technical knowledge by accessing journals, technical updates, suppliers' product notes and test methods

Required knowledge

Required knowledge includes:

sample preparation procedures including specialised techniques such as:

handling unstable/hazardous chemicals and samples and fragile/labile biological material

treatment of samples with high dissolved solids or high viscosity

filtration or centrifugation to remove particulates

open and closed wet chemical digestion and microwave digestion

alkali fusion of geological samples

contamination control and ultra-trace analysis requirements such as:

prevention of airborne contamination with filtered air systems and clean rooms

preparation of ultra pure acids and reagents

cleaning and storage of glass and plastic ware

prevention of personal contamination of samples by exposure to analyst

atomisation and ionisation mechanisms within inductively coupled plasmas:

effects of plasma temperature and stability on atomisation, single/double ionisation, recombination and matrix decomposition

isobaric interferences due to combinations of isotopes of argon (plasma gas), oxygen (sample solution), or chloride (matrix components) with themselves or other elements

calculations involving:

concentration and dilution

uncertainties

limit of detection, limit of quantitation and their application to quality control procedures

operation, construction, selectivity, typical applications, troubleshooting and routine maintenance of ICP-AES/OES and ICP-MS systems including details such as:

design and operation of nebulisers and characteristics such as aerosol efficiency, dissolved solid tolerance and self-aspiration

laser ablation of solid samples into aerosol form

design and operation of spray chambers and effects on sample flow, sensitivity, plasma loading from larger droplets

design and operation of plasma torches (e.g. tube diameter, sampling depth, radio frequency (RF) source) and effects on energy transfer, plasma stability, aerosol flow and density, matrix decomposition, deposition on the interface, polyatomic ion interferences and implications for cleaning

axial/radial torch configurations

design of sample/skimmer cones at plasma-vacuum interface and effects on sensitivity, mass response, oxide and doubly charged ion formation and loading on vacuum system

operation of rotary and turbo-molecular pumps and valves to provide high vacuum, typical pressures and flow rates

design and operation of electrostatic ion 'lenses' to separate analyte ions from neutral species and photons (to minimise background signal)

use of collision-reaction cells to remove interfering polyatomic ions

atomic/optical emission spectroscopy detectors (AES or OES), transfer optics, diffraction gratings, monochromators and polychromators, photomultipliers and charge coupled devices

MS (e.g. quadrupole, magnetic sector, sector field, ion trap and time of flight mass analysers, electron multipliers with pulse and/or analogue modes for ion detection, measurements including selective ion monitoring (SIM), time resolved analysis, isotope ratio measurements and full scan/multi-element analysis)

sources of AES/OES spectral interferences such as:

viscosity of sample

spectral overlap

ionisation

sources of MS spectral interferences such as:

isobaric interferences (e.g. 58Fe+ and 58Ni+)

polyatomic ions originating in gas, sample or matrix (e.g. 40Ar35Cl+ and 75As+, 44Ca16O+ and 60Ni+)

doubly charged ions such as Ba2+ interfering with 65Cu+, 66Zn+, 67Zn+, 68Zn+)

computer control software for operating and optimising instrument

procedures for optimising instrument (ICP-AES/OES or ICP-MS)performance such as:

effects of adjusting gas flow rates, torch residence time

investigation of plasma power/temperature on ionisation of analyte and interfering ions

optimising interface between ICP and MS detector (e.g. alignment of sample/skimmer cones and ion lens adjustment)

optimising plasma viewing height and for individual wavelengths for ICP-AES/OES

use of manual/computer calibration charts and/or standards to identify and quantify analytes such as:

external calibration with or without internal standardisation

method of standard additions

semi-quantitative analysis

isotope ratio measurements

isotope dilution

calculation steps to give results in appropriate units and precision

troubleshooting and maintenance procedures recommended by instrument manufacturer

enterprise and/or legal traceability requirements

relevant health, safety and environment requirements

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Codes of practice

Where reference is made to industry codes of practice, and/or Australian/international standards, it is expected the latest version will be used

Standards, codes, procedures and/or enterprise requirements

Standards, codes, procedures and/or enterprise requirements may include:

Australian and international standards, such as:

AS ISO 17025-2005 General requirements for the competence of testing and calibration laboratories

AS/NZS 2243 Set:2006 Safety in laboratories set

AS/NZS ISO 9000 Set:2008 Quality management systems set

AS 2830.1 Good laboratory practice - Chemical analysis

AS 4873 Set: 2005 Recommended practice for inductively coupled plasma mass spectroscopy (ICP-MS)

ISO 22036: 2008 Soil quality - Determination of trace elements in extracts of soil by inductively coupled plasma atomic emission spectroscopy (ICP-AES)

ISO 11885: 2007 Water quality - Determination of selected elements by inductively methods coupled plasma optical emission spectroscopy (ICP-OES) methods

ISO/IEC Guide 98-3:2008 Uncertainty of measurement - Part 3 Guide to the expression of uncertainty in measurement (GUM)

Eurachem/CITAC Guide CG4 Quantifying uncertainty in analytical measurement

NATA supplementary requirements for the field of testing

Australian code of good manufacturing practice (GMP)

principles of good laboratory practice (GLP)

material safety data sheets (MSDS)

national measurement regulations and guidelines

enterprise procedures, standard operating procedures (SOPs) and operating manuals

quality manuals, equipment and procedure manuals

equipment startup, operation and shutdown procedures

calibration and maintenance schedules

cleaning, hygiene and personal hygiene requirements

data quality procedures

enterprise recording and reporting procedures

material, production and product specifications

production and laboratory schedules

quality system and continued improvement processes

safety requirements for equipment, materials or products

sampling procedures (labelling, preparation, storage, transport and disposal)

schematics, work flows and laboratory layouts

statutory and enterprise occupational health and safety (OHS) requirements

stock records and inventory

test procedures (validated and authorised)

waste minimisation, containment, processing and disposal procedures

ICP instruments and techniques

Inductively coupled plasma instruments and techniques may include:

peristaltic sample pumps

nebulisers (e.g. cross-flow, V-groove, C spray, concentric, micro-concentric and ultrasonic)

spray chambers (temperature and pressure control)

alternative sample introduction systems such as:

laser ablation of solid samples

electrothermal vaporisation (ETV)

flow injection for samples high in total dissolved solids

chromatography (e.g. liquid and ion)

hydride generation

cold vapour mercury generation

plasma torch (RF generation and cooling), radial/axial alignment

plasma gas controls

interface (sample and skimmer cones) and ion lens

mass analysers such as:

quadrupole (peak jump mode, scan mode and single ion monitoring mode)

magnetic sector

time of flight

optical spectrum analysers (diffraction grating)

ion detectors (channeltron, electron multiplier tube and micro channel plate)

photon detectors (photomultiplier tubes and charge coupled devices)

replaceable items, such as valves, tubing and fittings, lamps, vacuum oil and argon gas

data systems, such as recorders, electronic integrators, and software packages for peak detection and integration

Testing that uses ICP spectroscopy

Testing that uses inductively coupled plasma spectroscopy may include:

medical (toxicology) testing of whole blood, urine, plasma, serum, packed red blood cells for:

exposure to heavy metals

metabolic function

forensic testing to establish elemental 'fingerprint' and possible source of scene of crime samples

environmental monitoring of pollution in air, water or soil

monitoring of waste water, sludges and trade effluents

control of starting materials, in-process materials and final products in a wide range of industry sectors (e.g. semi-conductor purity and ultra purity chemical reagents)

materials analysis (e.g. engine wear and oil analysis)

trace elements in food and wine

pharmaceuticals analysis (e.g. metal elements in drug products)

geological testing:

characterisation of rocks and minerals

analysis of mineral/ore samples during exploration, ore processing, final product quality

geochronology isotope ratio measurements

Presumptive tests

Presumptive tests may include:

pH

sample solubility in water and salinity

total dissolved solids

colour test

possible interferences and ion suppressants in sample matrix (e.g. presence of chlorides and chlorates)

Sample and standard preparation

Sample and standard preparation may include:

identification of any hazards associated with the samples and/or analytical chemicals

grinding, dissolving, extraction, filtration, refluxing, centrifuging, evaporation, washing and drying

digestion in nitric acid or aqua regia or hydrogen fluoride for geological samples

microwave digestion

determination of, and if appropriate, removal of any contaminants or impurities or interfering substances

ultra-trace procedures requiring high purity solvents, clean rooms, ultra clean glassware and specialised glassware

preparation of internal standards, such as Indium and/or Gallium

Pre-use, calibration and safety checks

Pre-use, calibration and safety checks may include:

cleanliness of sample/skimmer cones, spray chamber and sample injection/nebuliser orifices

cleanliness of RF coils and quartz tubes

condition of sample and waste tubing on peristaltic pump lines

alignment of torch central tube with sample cone

initial mass calibrations (e.g. He isotopes in air, argon or other gases)

resolution checks

use of Rhodium levels, Cerium/oxide ratios and de-ionised water blanks to test sensitivity and alignment

Instrumental parameters

Instrumental parameters may include:

ICP parameters:

manual/auto sample, pump program, pre- and post-sample washes

sample introduction rate and sample uptake rate

nebuliser/water flow rates

torch gas flow rates

adjustment of plasma temperature to optimise ionisation and minimise interferences (e.g. oxide)

OES/AES detector/source control parameters:

wavelength choice for element sensitivity and/or interference

photomultiplier and charge coupled device

MS parameters:

vacuum pressures and gas flows

sample and skimmer cone alignment

sampling depth (distance between torch and sampling cone tip)

ion optics voltage

mass analyser control

detector settings, such as discriminator voltage, detector high voltage, dead time correction and dual mode/extended range detector calibration

scan, mass start/end, scan time and inter-scan delay

selective ion monitoring (SIM)

Common analytical procedure problems and remedies

Common analytical procedure problems and remedies may include:

lack of suitable reference standards

poor sensitivity

overlapping spectra

nebuliser interferences, such as changes in sample delivery rate, nebuliser efficiency and droplet size

MS polyatomic interferences, reduced by:

cooling the spray chamber to 2-50C

desolvating the aerosol using a condenser and/or semi-permeable membrane

using alternative sample introduction methods

reducing chlorides by using nitric acid digests

adding gases such as H2, N2 and CH4 to the inner, intermediate or outer gases

adding ethanol to the sample to reduce ArCl+

using spectral line fitting software

using cold plasma conditions

using correction equations

using a collision or reaction cell

MS non-spectral (matrix) interferences, reduced by:

matrix matching of calibration and sample solutions

equilibrating test sample solutions to room temperature

removal of dissolved gases from sample solutions

dilution of sample solution

using internal standards (i.e. reference elements)

analyte additions

isotope dilution

Common equipment problems

Common equipment problems may include:

system leaks

efficiency of rotary pump (oil and bearing wear) and turbo/molecular pumps

flat spots in sample/peristaltic pump tubing causing irregular sample or solvent delivery

contamination of sample, solvents, lines or other system elements

build up of salts/dissolved solids in sample valves, torch, MS spray chamber and/or cones

Hazards

Hazards may include:

electric shock

biohazards, such as microbiological organisms and agents associated with soil, air, water, blood and blood products, and human or animal tissue and fluids

corrosive chemicals

sharps and broken glassware

flammable liquids and gases

fluids under pressure, sources of ignition

disturbance or interruption of services

toxic fumes and ozone (plasma exhaust)

non-ionising radiation (UV and RF)

Addressing hazards

Addressing hazards may include:

use of MSDS

accurate labelling of samples, reagents, aliquoted samples and hazardous materials

personal protective equipment, such as gloves, safety glasses and coveralls

use of fumehoods, direct extraction of vapours and 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, MSDS and manufacturer's instructions

Occupational health and safety (OHS) and environmental management requirements

OHS and environmental management requirements:

all operations must comply with enterprise OHS and environmental management requirements, which may be imposed through state/territory or federal legislation - these requirements must not be compromised at any time

all operations assume the potentially hazardous nature of samples and require standard precautions to be applied

where relevant, users should access and apply current industry understanding of infection control issued by the National Health and Medical Research Council (NHMRC) and State and Territory Departments of Health