NTISthis.com

Evidence Guide: MSL974001A - Prepare, standardise and use solutions

Student: __________________________________________________

Signature: _________________________________________________

Tips for gathering evidence to demonstrate your skills

The important thing to remember when gathering evidence is that the more evidence the better - that is, the more evidence you gather to demonstrate your skills, the more confident an assessor can be that you have learned the skills not just at one point in time, but are continuing to apply and develop those skills (as opposed to just learning for the test!). Furthermore, one piece of evidence that you collect will not usualy demonstrate all the required criteria for a unit of competency, whereas multiple overlapping pieces of evidence will usually do the trick!

From the Wiki University

 

MSL974001A - Prepare, standardise and use solutions

What evidence can you provide to prove your understanding of each of the following citeria?

Prepare solutions

  1. Select appropriate procedure for solution preparation
  2. Select equipment, materials and solvent of specified purity
  3. Measure appropriate quantities of reagents for solution preparation and record data.
  4. Select and assemble specified laboratory equipment and appropriate grade of glassware
  5. Perform specified dilutions
  6. Prepare solutions to achieve homogeneous mix of the specified concentration
  7. Label and store solutions to maintain identity and stability
Select appropriate procedure for solution preparation

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Select equipment, materials and solvent of specified purity

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Measure appropriate quantities of reagents for solution preparation and record data.

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Select and assemble specified laboratory equipment and appropriate grade of glassware

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Perform specified dilutions

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Prepare solutions to achieve homogeneous mix of the specified concentration

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Label and store solutions to maintain identity and stability

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Standardise and use volumetric solutions

  1. Assemble appropriate laboratory equipment
  2. Perform serial dilutions as required
  3. Standardise the solution to the required specified range and precision
  4. Label and store solutions to maintain identity and stability
  5. Use standard volumetric solutions to determine concentration of unknown solutions
Assemble appropriate laboratory equipment

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Perform serial dilutions as required

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Standardise the solution to the required specified range and precision

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Label and store solutions to maintain identity and stability

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Use standard volumetric solutions to determine concentration of unknown solutions

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Calculate and record data

  1. Calculate specified concentrations
  2. Use authorised procedure if data is to be modified
  3. Estimate and document uncertainty of measurement in accordance with enterprise procedures, if required
  4. Record all relevant details according to laboratory procedures and report results
  5. Report concentration with appropriate units
Calculate specified concentrations

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Use authorised procedure if data is to be modified

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Estimate and document uncertainty of measurement in accordance with enterprise procedures, if required

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Record all relevant details according to laboratory procedures and report results

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Report concentration with appropriate units

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Monitor the quality of laboratory solutions

  1. Check solutions for visual deterioration and expiry date
  2. Restandardise or dispose of dated or deteriorated solutions
  3. Record details and label solutions according to laboratory procedures
Check solutions for visual deterioration and expiry date

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Restandardise or dispose of dated or deteriorated solutions

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Record details and label solutions according to laboratory procedures

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Maintain a safe work environment

  1. Use established safe work practices and personal protective equipment to ensure personal safety and that of other laboratory personnel
  2. Clean up spills using appropriate techniques to protect personnel, work area and environment
  3. Minimise generation of waste and environmental impacts
  4. Ensure the safe collection of laboratory and hazardous waste for subsequent disposal
  5. Store equipment and reagents as required
Use established safe work practices and personal protective equipment to ensure personal safety and that of other laboratory personnel

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Clean up spills using appropriate techniques to protect personnel, work area and environment

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Minimise generation of waste and environmental impacts

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Ensure the safe collection of laboratory and hazardous waste for subsequent disposal

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Store equipment and reagents as required

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Assessed

Teacher: ___________________________________ Date: _________

Signature: ________________________________________________

Comments:

 

 

 

 

 

 

 

 

Instructions to Assessors

Evidence Guide

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:

use balances and volumetric glassware

select and use primary and secondary standards

select and use indicators

perform quality assurance checks for solution performance

perform titrations using laboratory procedures with required accuracy and precision and within required timelines

calculate the concentration of the solution given the chemical reaction for the titration

recognise control results that are not within acceptable range

record results to enterprise standards

label and store solutions in accordance with enterprise procedures

interpret and follow enterprise SOPs

interpret and use safety information, such as that provided by MSDS and follow relevant safety procedures.

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:

relevant MSAL974000 series units of competency, and

relevant MSAL975000 series units of competency dealing with sampling, tests and measurements.

Resources may include:

standard laboratory equipped with appropriate volumetric equipment

laboratory reagents and equipment

SOPs and testing methods.

Method of assessment

The following assessment methods are suggested:

inspection and/or testing of solutions prepared by the candidate

review of records and workplace documentation completed by candidate

review of work outputs by the candidate over time to ensure accuracy, consistency and timeliness

feedback from peers and supervisors

observation of the candidate preparing, standardising and using a range of 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.

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.

Manufacturing

A standard solution is used to determine the concentration of unknown solutions. The quality of these analyses is critically related to the accuracy with which the concentration of the standard solution is known. Therefore, laboratory technicians spend considerable effort to ensure that the materials and methods used for the preparation and standardisation will lead to a solution of accurately known concentration. For example, anhydrous sodium carbonate is often used to prepare solutions to determine the concentrations of acids. The sodium carbonate is heated at a suitable temperature to remove any trace of moisture and cooled in a dessicator. An appropriate quantity is dissolved in distilled water and made up to volume in a volumetric flask. This solution of known concentration is then titrated with acids of unknown concentration and the concentration of the acids determined.

Environmental

A laboratory technician was required to determine the total acidity of a water sample as part of a quality control program. The total acidity was measured by titrating the water sample with sodium hydroxide of known concentration using an appropriate indicator. The concentration of the sodium hydroxide was determined via a volumetric titration against a primary standard of potassium hydrogen phthalate.

The value of the total acidity was determined by multiplying the volume of sodium hydroxide used with a numerical 'factor' which had been determined by the laboratory supervisor in order to save time. The value of the 'factor' was displayed on the titration equipment. However, a new technical assistant did the full calculation and found that his/her result differed slightly from that obtained using the 'factor'. After discussion with the laboratory supervisor it was agreed that the error was in the 'factor' and the assumption that each new batch of sodium hydroxide prepared was exactly the same concentration as all previous batches. This was incorrect as the concentration of each batch differed slightly and its actual concentration was determined accurate, using the primary standard. The procedure was changed so that the full calculation was required for all tests.

Required Skills and Knowledge

Required skills

Required skills include:

interpreting and following enterprise standard operating procedures (SOPs)

determining equivalence points using indicators and graphical methods

using calculation methods, including appropriate units, uncertainties, balancing equations, the concentration of the solution given the chemical reaction for the titration

using apparatus and reagents to prepare standard solutions such as balances and volumetric glassware

selecting and using primary and secondary standards and indicators

performingquality assurance checks for solution performance

performing titrations

recognising control results that are not within acceptable range

interpreting and using safety information, such as that provided by material safety data sheets (MSDS) and follow relevant safety procedures

Required knowledge

Required knowledge includes:

solution terminology, chemistry of acids, bases, buffers, redox reactions and complexiometric reactions

concepts of metrology

grades of glassware, reagents and their use

reactions used for standardisation and desirable characteristics

enterprise communication and reporting procedures

occupational health and safety (OHS) procedures, including those for using corrosive materials

relevant health, safety and environment requirements

Range Statement

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 2163-2000 Laboratory glassware - Measuring cylinders

AS 2165-1996 Laboratory glassware - Burettes AS 2162.1-1996 Verification and use of volumetric apparatus - General - Volumetric glassware

AS ISO 1000-1998 The international system of units (SI) and its application

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

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

AS/NZS 2243 Set:2006 Safety in laboratories set

Australian code of good manufacturing practice for medicinal products (GMP)

calibration and maintenance schedules

enterprise recording and reporting procedures

equipment manuals

equipment startup, operation and shutdown procedures

MSDS and safety procedures

material, production and product specifications

national measurement regulations and guidelines

principles of good laboratory practice (GLP)

production and laboratory schedules

quality manuals

SOPs

waste minimisation and safe disposal procedures

Solutions

Solutions may include but are not limited to:

solutions of strong/weak acids and bases

oxidising/reducing agents

solutions used for complexometric or precipitation titrations

stains for cells and tissues, enzymes, buffers and antibodies

diluents for maintaining isotonicity

organic solutions and histological fixatives

Apparatus and reagents to prepare standard solutions

Apparatus and reagents to prepare standard solutions may include:

balances

pipettes, burettes, volumetric glassware and weighing bottles

dessicators and filtering media

ovens and muffle furnaces

solutions, indicators and primary and secondary standards

auto titrators, pH meters and other related meters and electrodes for determining equivalence points, top pan and analytical balances

magnetic stirrers and heaters, and water baths

Checking useability of solutions

Checking useability of solutions may include:

examining stained samples for correct staining reactions

performing pH checks

confirming enzyme activity

checking red cell suspensions for haemolysis

ferric chloride for phenolic solutions

isotonicity for saline

Hazards

Hazards may include:

chemicals, such as strong acids and bases, and stains

sharps and broken glassware

burners, hot plates, ovens and furnaces

Safe work practices

Safe work practices may include:

use of MSDS

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

use of biohazard containers, laminar flow cabinets and fume hoods

correct labelling of reagents and hazardous materials

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

regular cleaning and/or decontaminating of equipment and work areas

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