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 a variety of LC sample valves, solvent delivery components, pumps, columns and detectors

install injectors, solvent delivery systems and columns

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 LC instruments to measure analytes

feedback from clients, peers and supervisors

oral or written questioning of relevant LC 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 and beverage processing

A technician is measuring phosphate levels in samples of a popular cola drink by ion chromatography. Using a standard method, he/she notes that there is a long retention time and obtains a broad asymmetric peak because the recommended flow rate could not be obtained with the laboratory's instrument. He/she then decides that the simplest way to speed up the elution time is to modify the mobile phase by increasing the % of methanol. The technician was pleased to obtain a well resolved analyte peak despite the faster eluting peaks now being unresolved. However, this was of no consequence to the analysis as the client only required the phosphate concentration.

Education and training

An experienced technician sets up and runs some pre-use checks for an LC instrument that is used by several laboratory personnel with periods of downtime in between. To his/her dismay, the initial standard produces one broad peak instead of three pronounced UV absorbance peaks as expected. He/she checks that the column has not been changed and that the mobile phase composition and flow rates are correct. He/she then checks each sub-system carefully and then waits for the system to equilibrate again. After re-running the standard, the result is the same and so he/she then suspects something is wrong with the stationary phase. The technician notices that when the instrument was last used, the mobile phase had a high percentage of water. He/she now suspects that there is bacterial growthin the column because it has been stored incorrectly. After trying to regenerate the column unsuccessfully, the technician installs a new one and then flushes and conditions the instrument in accordance with the laboratory procedures.

He/she then adds the following information to the instrument logbook:

Store columns in 50/50 methanol/water without any acid.

If you are using a salt, unlikely in LC-MS, wash the entire system, solvent bottles, LC, solvent lines, and column, in a non-salt containing solvent. (Otherwise salt may precipitate out and plug your LC or column or may cause corrosion.)

Flush with pure water first and then leave the system in 50/50 methanol/water mixture. (Some salts may precipitate out in high organics so an initial water wash is advised.The 50/50 methanol/water solution helps to stop bacterial growth which can muck up the system!

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 (including consideration of suitable polar/non-polar stationary and mobile phases, solvent composition, compatibility of sample solvent with mobile phase, buffer, sample loop volume, temperature, flow rate, column type, column length and detection)

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, ensuring safe collection and disposal

applying relevant principles of good laboratory (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, fragile/labile biological material

liquid-liquid extraction, solid-phase micro extraction, derivatisation, filtering and dilution/concentration

principles for separation of analytes such as:

chemical composition of stationary and mobile phases and their types of interaction

selection of solvents based on polarity, viscosity, ultraviolet (UV) cut-off

requirements for solvent purity and pre-treatment including filtration, degassing, buffering and modifying solvents

isocratic and gradient elution flow programming (linear, concave and convex gradients and step)

recovery and recycling of solvents

separation by polarity:

normal phase systems and hydrophilic (interaction chromatography)

reverse phase systems and hydrophobic (interaction chromatography)

order of elution in normal and reverse phase systems

separation by charge:

ion exchange chromatography(IEC) and ion chromatography (IC)

ion suppression and ion pairing techniques

non-suppressed systems

separation based on molecular size:

size exclusion chromatography (SEC)

gel-permeation chromatography (GPC)

relationship between retention time and molecular mass

bioaffinity chromatography principles

chromatography concepts and calculations involving:

retention times, peak widths, peak asymmetry, capacity factor k' and resolution

column selectivity, column efficiency (plates/m), optimum flow rate, minimum theoretical plate height, Van Deemter and related equations

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

operation, construction, selectivity, typical applications, troubleshooting and routine maintenance of LC columns including:

(semi) preparation columns, packed columns and capillary columns

column oven (role of temperature in achieving close separations)

checking for leaks, changing of columns, lines and valves

system flushing and conditioning and storage of columns

operation, construction, selectivity, typical applications, troubleshooting and routine maintenance of LC sample introduction systemsincluding:

manual and auto-injection, injector valves, solvent reservoirs, selector valves, gradient programmer, mixing manifolds and column switching

pump designs such as reciprocating piston or diaphragm, pressures, flow rates

operation, construction, selectivity, sensitivity, linear range, typical applications, troubleshooting and routine maintenance of LC detectors including:

UV fixed wavelength and dispersion/diode array multi-wavelength detectors

conductivity detector (ECD)

electrochemical detector (ECD)

fluorescence detectors

refractive index (RI)

evaporative light scattering (ELSD)

mass spectrometry (LC-MS) (LC-MS-MS) using full scan or selective ion monitoring (SIM)

flow splitting, tandem detectors (e.g. UV and MS)

routine quality control procedures such as use of manual/computer calibration charts and/or standards

computer control software for operating and optimising instrument (peak detection and integration, drift parameters, baseline correction and instrument/integrator zero)

procedures for optimising instrument performance such as:

optimising separation by changing solvent composition including use of mobile phase gradient computer control programs

investigation of elution order in normal and reverse phase systems

effects on instrumental outputs and analytical results by fine tuning injection, mobile phase flow rate, column pressures and changing column type or detector

aligning MS interface cones

steps in identifying and quantifying analytes including relative retention data, peak area normalisation and response factors

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 3741 Recommended practice for chemical analysis by ion chromatography

BS EN 12916 Petroleum products - Determination of aromatic hydrocarbon types in middle distillates - HPLC method with refractive index detection.

DIN EN 12630 Fruit and vegetable juices - Determination of glucose, fructose, sorbitol and sucrose - Method by HPLC.

ISO 10304 set Water quality - Determination of dissolved anions by LC of ions

ISO 20481 Coffee and coffee products - Determination of caffeine content using HPLC

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

LC instruments and techniques

LC instruments and techniques may include:

analytical and (semi) preparative columns

sample and solvent introduction systems such as:

sample valves, sub µL, µL and mL

sample loop design

solvent selector valves, mixing manifolds, binary/quaternary pumps and control program

LC detectors such as:

UV absorbance

conductivity detector (ECD)

electrochemical detector (ECD)

fluorescence

refractive index (RI)

evaporative light scattering (ELSD)

'hyphenated' mass spectrometry (LC-MS) (LC-MS-MS)

fraction collectors

replaceable items, such as sample injection valves, (high pressure) tubing and fittings, column connectors and lamps

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

Testing that uses LC instruments

Testing that uses liquid chromatography instruments may include:

determination of the molecular weight distribution for large molecules such as proteins and polymers

therapeutic drug analysis

diagnostic pathology tests

forensic testing of samples (e.g. toxicology, dyes and inks)

environmental monitoring of pollution in air, water or soil (e.g. herbicides, pesticides, nitrates and phosphates)

control of starting materials, in-process materials and final products in the food, beverage and pharmaceutical industry sectors

Presumptive tests

Presumptive tests may include:

pH

sample solubility in water/methanol mix (free of precipitates and miscible in one phase)

colour test

compatibility of sample solvent and mobile phase

Sample preparation

Sample preparation may include:

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

derivatisation

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

solid-phase micro-extraction

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

on column concentration

Instrumental parameters

Instrumental parameters may include

LC parameters:

manual/auto sample; injector volume, pre- and post-sample washes

fixed or variable solvent ratios

solvent flow rate

column temperature

detector/source parameters, single/split system

MS parameters:

vacuum pressures and gas flows

nebuliser gas flow

ionisation control

interface cone alignment

ion lens voltage

mass analyser control

solvent delay

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

selective ion monitoring (SIM)

Common analytical procedure and equipment problems

Common analytical procedure and equipment problems may include:

system leaks

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

irregular sample or solvent delivery

contamination of sample, solvents, lines or other system elements

dead volume

bubbles in system

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

lack of suitable reference standards

poor separation due to inappropriate selection of column or operating parameters solvent mix and flow

poor sensitivity

absence of peaks and presence of ghost peaks, split peaks or distorted peak shapes and broad solvent peaks

baseline instability and non-reproducible retention times

Hazards

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

corrosive chemicals

sharps and broken glassware

hot surfaces

flammable liquids and gases

fluids under pressure and sources of ignition

disturbance or interruption of services

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, 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, 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