Unit of Competency Mapping – Information for Teachers/Assessors – Information for Learners

PMLTEST303B Mapping and Delivery Guide
Prepare working solutions

Version 1.0
Issue Date: March 2024


Qualification -
Unit of Competency PMLTEST303B - Prepare working solutions
Description This unit of competency covers the ability to prepare working solutions and to check that existing stocks are suitable for use. This unit assumes that calculations of quantities, choice of reagent grades and required dilutions will be specified by the supervisor.This unit of competency has no prerequisites.This unit of competency is applicable to laboratory assistants working in all industry sectors.Industry representatives have provided case studies to illustrate the practical application of this unit of competency and to show its relevance in a workplace setting. These are found at the end of this unit of competency under the section This competency in practice.
Employability Skills
Learning Outcomes and Application
Duration and Setting X weeks, nominally xx hours, delivered in a classroom/online/blended learning setting.
Prerequisites/co-requisites
Competency Field
Development and validation strategy and guide for assessors and learners Student Learning Resources Handouts
Activities
Slides
PPT
Assessment 1 Assessment 2 Assessment 3 Assessment 4
Elements of Competency Performance Criteria              
Element: Safely use laboratory chemicals, glassware and equipment
  • Apply appropriate safety precautions for use of laboratory equipment and hazardous chemical materials
  • Use appropriate laboratory glassware and measuring equipment
  • Clean and store glassware and equipment in accordance with enterprise procedures
       
Element: Make up working solutions
  • Identify the relevant standard methods for solution preparation
  • Assemble specified laboratory equipment
  • Select and prepare materials and solvent of specified purity
  • Measure appropriate quantities of reagents for solution preparation and record data
  • Transfer solutions to appropriately labelled containers
       
Element: Check existing stock of solutions
  • Monitor shelf-life of working solutions as per laboratory procedures
  • Replace out-of-date or reject solutions as per laboratory procedures
  • Conduct routine titrimetric analyses, if appropriate, to determine if solutions are fit for purpose.
       


Evidence Required

List the assessment methods to be used and the context and resources required for assessment. Copy and paste the relevant sections from the evidence guide below and then re-write these in plain English.

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, the assessor should look to see that the candidate:

uses appropriate materials, equipment and procedures to prepare solutions

follows appropriate OHS (and hygiene, if appropriate) procedures

uses all equipment safely, efficiently and in accordance with enterprise procedures

uses enterprise procedures to calculate concentrations

identifies solutions not fit for use

uses titrations to determine the concentration of solutions

labels, stores and disposes of solutions appropriately

records and present data appropriately.

Underpinning knowledge

Competency includes the ability to apply and explain:

relevant biological, chemical, food and laboratory terminology

basic theory of acids, bases, salts, buffers and neutralisation

enterprise procedures for preparing solutions

calculations required to prepare specified amounts of solutions of specified concentration

appropriate OHS procedure for preparing, handling and disposal of solutions

use of MSDSs

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:

inspection of solutions prepared, labelled and stored by the candidate

review of solution records and workplace documentation completed by the candidate

feedback from peers, and supervisors

observation of the candidate preparing working solutions

oral or written questioning.

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:

PMLDATA200A Record and present data

PMLOHS302A Participate in laboratory/field workplace safety.

Resource implications

Resources may include:

standard laboratory equipped with appropriate equipment and reagents

standard operating procedures and testing methods

access to appropriate containers and storage facilities.

This competency in practice

Manufacturing

When starting materials used for the manufacture of common household materials are in transit from the supplier to the manufacturer, they may degrade if subjected to conditions, such as heat, moisture, light and oxygen. Even when the supplier ships quality materials to the manufacturing plant, the materials may be substandard when they arrive. Quality control tests are designed to test starting materials to ensure they are within specification. For example, aspirin forms salicylic acid when stored under adverse conditions. Laboratory assistants prepare and monitor the quality of solutions, such as ferric chloride solution, which gives an intense violet colour when added to salicylic acid but gives no colour with aspirin. Absence of the violet colouration indicates that breakdown of the aspirin hasn't occurred.

Biomedical

A laboratory assistant made up 1 litre of buffer solution using buffer tablets and a 1 litre volumetric flask as specified in the method. To ensure the solution was suitable for use, the assistant measured the pH and found it was within acceptable range. The assistant then appropriately labelled a storage vessel and stored the buffer according to requirements. By following enterprise procedures the shelf life of the buffer was maximised.

Environmental

An environmental laboratory is contracted to determine the acidity of water samples taken from local lakes and streams. A laboratory assistant is required to make up small batches of 0.01M sodium hydroxide and to determine its concentration by titrating it against a standard solution of potassium acid phthalate using phenolphthalein indicator. This procedure is carried out monthly to ensure that the concentration of the sodium hydroxide solution is accurately known. Alternatively, the laboratory assistant may be required to prepare and standardise a fresh batch of sodium hydroxide on a monthly basis. In this case, he/she must understand the underpinning knowledge of basic acid/base theory, potential problems of interferences (such as slow absorption of carbon dioxide by sodium hydroxide solution) so as to ensure that the concentrations of workup solutions are accurately known. He/she must also be skilled in calculating and performing dilution when required to prepare such low concentrations (0.01M) of working solutions.

Key Competencies

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 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.

Collecting, analysing and organising information

Communicating ideas and information

Planning and organising activities

Working with others and in teams

Using mathematical ideas and techniques

Solving problems

Using technology

Level 1

Level 1

Level 1

Level 1

Level 1

Level 1

Level 1


Submission Requirements

List each assessment task's title, type (eg project, observation/demonstration, essay, assignment, checklist) and due date here

Assessment task 1: [title]      Due date:

(add new lines for each of the assessment tasks)


Assessment Tasks

Copy and paste from the following data to produce each assessment task. Write these in plain English and spell out how, when and where the task is to be carried out, under what conditions, and what resources are needed. Include guidelines about how well the candidate has to perform a task for it to be judged satisfactory.

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.

This unit of competency describes the work conducted by supervised laboratory assistants who prepare a range of working solutions for laboratory use. Test solutions include those required to perform laboratory tests. 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 2162.1 General - volumetric glassware

AS 2163 Laboratory glassware - measuring cylinders

AS 2165 Laboratory glassware - burettes

industry methods, such as American Association of Cereal Chemists (AACC) Solution methods

Codes of Practice, such as GLP and GMP

material safety data sheets (MSDSs)

National Measurement Act

standard operating procedures (SOPs)

equipment manuals

equipment startup, operation and shutdown procedures

calibration and maintenance schedules

quality manuals

enterprise recording and reporting procedures

production and laboratory schedules

material, production and product specifications.

The nature of test solutions will depend on the enterprise and the range of testing carried out. Typical test solutions may include:

solutions required for diagnostic/analytical and limit tests in food and chemical laboratories, such as sulphates, chlorides, heavy metals

solutions, such as stains for standard diagnostic/analytical procedures in biomedical/environmental laboratories, such as cell staining, fixation of cells and tissues, suspension of cells, titrimetric indicators

solutions required for laboratory maintenance and disinfection, such as 70% ethanol, hypochlorite.

Laboratory equipment may include:

pH meters

balances

magnetic stirrers, waterbaths and hot plates

measuring cylinders, beakers, conical flasks, volumetric flasks, pipettes, burettes

filter papers and funnels

fume cupboards.

Hazards may include:

corrosive chemicals, such as acids and alkalis

sources of heat, such as burners

sharps, broken glassware

spillages.

Safety precautions may include:

use of material safety data sheets (MSDSs)

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

correct labelling of reagents and hazardous materials

handling and storing hazardous materials and equipment in accordance with labels, MSDS, manufacturer's instructions, enterprise procedures and regulations

regular cleaning and/or decontamination of equipment and work areas.

Monitoring quality of solutions can include:

noting turbidity to exclude absorption of moisture

noting deposits to exclude microbial contamination or chemical degradation

noting crystals to exclude evaporation

conducting titrations to check concentration

noting colour changes indicating a pH shift with solutions containing indicators

checking expiry dates on solution containers.

Concentration terms may include: % w/w, % w/v, % v/v, ppm (mg/L), molarity.

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.

Copy and paste from the following performance criteria to create an observation checklist for each task. When you have finished writing your assessment tool every one of these must have been addressed, preferably several times in a variety of contexts. To ensure this occurs download the assessment matrix for the unit; enter each assessment task as a column header and place check marks against each performance criteria that task addresses.

Observation Checklist

Tasks to be observed according to workplace/college/TAFE policy and procedures, relevant legislation and Codes of Practice Yes No Comments/feedback
Apply appropriate safety precautions for use of laboratory equipment and hazardous chemical materials 
Use appropriate laboratory glassware and measuring equipment 
Clean and store glassware and equipment in accordance with enterprise procedures 
Identify the relevant standard methods for solution preparation 
Assemble specified laboratory equipment 
Select and prepare materials and solvent of specified purity 
Measure appropriate quantities of reagents for solution preparation and record data 
Transfer solutions to appropriately labelled containers 
Monitor shelf-life of working solutions as per laboratory procedures 
Replace out-of-date or reject solutions as per laboratory procedures 
Conduct routine titrimetric analyses, if appropriate, to determine if solutions are fit for purpose. 

Forms

Assessment Cover Sheet

PMLTEST303B - Prepare working solutions
Assessment task 1: [title]

Student name:

Student ID:

I declare that the assessment tasks submitted for this unit are my own work.

Student signature:

Result: Competent Not yet competent

Feedback to student

 

 

 

 

 

 

 

 

Assessor name:

Signature:

Date:


Assessment Record Sheet

PMLTEST303B - Prepare working solutions

Student name:

Student ID:

Assessment task 1: [title] Result: Competent Not yet competent

(add lines for each task)

Feedback to student:

 

 

 

 

 

 

 

 

Overall assessment result: Competent Not yet competent

Assessor name:

Signature:

Date:

Student signature:

Date: