Essential Laboratory Skills Guide – recognize and avoid potential error sources and ultimately increase laboratory efficiency
Our "Essential Laboratory Skills" Guide supports lab operators to recognize and avoid potential error sources and ultimately increase laboratory efficiency.
Experience shows that modern, well-developed balances and analytical instruments do the most to promote ease of use, operational safety and accurate results. However, even with state-of-the-art solutions, practical know-how is still required for users to do things right and achieve reliability and consistency.
Basic measurement techniques covered in this guide include: Weighing, Pipetting, pH Measurement, Moisture Content, Titration, UV/VIS, Density & Refractive Index, Melting, Dropping, Boiling, Cloud and Slip Melting Point and Thermal Analysis.
Each section follows a similar structure:
- Measurement techniques
- Tips gained from real-life lab experience
- Method discussion and application examples
- Selected solutions from our portfolio
Essential Laboratory Skills
A Guide for Measurement Quality in the Lab
1. General Introduction
Table of contents:
4. pH and Conductivity Value Determination
5. Moisture Content Determination
8. Density – Concentration Determination
9. Refractive Index – Concentration Determination
10. Melting, Dropping, Boiling, Cloud and Slip Melting Point
11. Thermal Analysis
12. Selected Solutions
15. Additional Supporting Information
Measuring for Success
All labs strive for accuracy and efficiency. No matter the measurement instrument being used, the goals of accuracy and workflow efficiency are foundational and straightforward. Obtaining measurement accuracy in a world that is constantly changing, however, can be anything but straightforward. And to miss this overarching goal can be detrimental, because undetected errors breed exponentially. One poor-quality result affects not just the measurement in question but every measurement that comes after it. And when accuracy suffers, lab outcomes and profit margins suffer as well: Time-consuming efforts must be repeated. End-users can even come to harm.
To have the best chance at obtaining accuracy, a lab operator must first have a clear understanding of basic measurement techniques and the operating principles of equipment he or she is using. This understanding helps the operator recognize and avoid potential error sources. It can also allow them to seek ways to redesign workflows and ultimately increase efficiency. In a modern lab, instruments must “play well together” for reliable sample quality assessment and seamless measuring processes.
Measurement Accuracy and Workflow Efficiency Impetus
To ensure the ongoing thrive for measurement accuracy and workflow efficiency in any lab, three basic operational building blocks must be applied:
- User Training. Effective training ensures people who use instruments day-in, day-out gain thorough knowledge about the criticality of accuracy in a given process. It also ensures they have the ability to watch and compensate for potential error sources.
- Routine Maintenance. The crucial action of instituting an adequate maintenance schedule for all lab equipment helps to ensure reliable instrument performance and flawless instrument uptime.
- Process Security. Sound data management, workflow automation and user management all help contribute to data integrity and security.
While all three aspects are important, this guide will focus on providing knowledge and tips that supplement in-lab training efforts and help ensure operators understand the intricacies of individual measurement methods. This information will not only help to reduce errors; it will also provide insight into scenarios where automation can help increase productivity.
Exploring Measurement Principles
Basic measurement techniques covered in this guide include:
- Weighing – a key activity in most laboratories, though often underestimated. This guide will help to understand factors influencing weighing and how their effects can be minimized or avoided.
- Pipetting – a mainstay of biotech and research labs. While appearing straightforward, liquid handling skills may differ considerably among operators. This guide will help lab personnel mitigate sources of inconsistency for enhanced long-term accuracy.
- pH Measurement – an important value for many applications, products and processes. Operators will learn some tips and tricks about meters and electrodes helping to reach correct and reliable pH results time by time.
- Moisture Content – critical to many products and industries, it guides everything from product quality and performance to shelf life. This guide briefly explains the principle of halogen moisture analyzers and how precise and reliable results can be achieved in routine moisture analysis.
- Titration – its dependability stems from the reliable and stoichiometric course of the titration reaction, generally accepted methods and well-proven instruments. This guide will help operators assess and develop optimal titrations.
- UV/VIS – UV/VIS spectroscopy is routinely used in analytical chemistry for the quantitative determination of different analytes, such as transition metal ions, highly conjugated organic compounds and biological macromolecules. This guide presents tips how to get accurate results, quickly.
- Density & Refractive Index – provide critical quality control information. Both methods easily deliver fast results which make them ideal for routine analyses. However, an understanding of measurement principles and the application of operational excellence help reach reliable results and keep product attributes stable at target.
- Melting, Dropping, Boiling, Cloud and Slip Melting Point – all parameters yield material characterizing values based on the same general methodology: controlled heating until a defined event based on a phase transition is detected. Tips presented about operation and sample preparation are essential and prerequisite for accurate results.
- Thermal Analysis – encompasses a range of techniques that allow to characterize materials under controlled temperature and time programs. Operators will learn the different thermal analysis techniques and a systematic approach to method development.
Each section follows a similar structure: the measurement technique itself, principles that support accuracy, tips gained from real-life lab experience, and a reference to other valuable knowledge materials including guides and white papers on the topic.
Using Methods in Concert
In many modern labs, multiple determinations run in parallel – for example, more than one moisture analyzer or titrator are in use at a time, each assessing a single parameter on one sample. The interplay among instruments creates an overall quality picture. Ongoing quality results may be catalogued in a central repository, such as METTLER TOLEDO’s LabX software, for easy recall and trending.
Multiple determinations may also be made in a single sample or sample type. For example, a lab may have a single automated system for determining the conductivity, pH value and alkalinity of water, or multiple titrators combined in one workflow to look at nickel content and hypophosphite content of electroplating samples. Again, a central data repository such as LabX compiles the results of the determinations into a usable quality snapshot. For dedicated METTLER TOLEDO solutions, see chapter 12.