Understanding Integration parameters

• Peak width
• Peak threshold
• Skim ratio
• valley-Valley
• Min Height
• Min Area
• Force peak start and end
• Force horizontal baseline
• Negative peaks
• Integration on/off
• Using highlight colours
• Grouping peaks

integration by height or area

Time windows

Using a reference peak

Calibration Options:

• External Standard
• Internal Standard
• Area %
• Standard Addition
• Correlation Factor

When to use single point or multipoint calibration

When you might accept a curve instead of a straight line

• the risks
• how to get a straight lin even if the results give a curve

What is an acceptable r2 value

Preparation of calibration standards

• master standard and dilutions
• Selecting appropriate weights and volumes
• choice of sample solvent

Temperature control - the importance and the pitfalls

• in the lab
• in the autosampler

Bracketed Calibration

Calibration range

Why a calibration curve may not go through zero

Using zero as a point in the calibration curve

The use of blank samples

• proving zero is zero
• checking for carryover
• ghost peaks

Limit of Detection

Limit of Quantitation

What can threaten the integrity of a calibration

• systematic errors
• random errors
• retention time reproducibility (peak area change and incorrect peak assignment)
• purity of standards
• temperature changes
• peak shape changes
• increasing noise
• detector maintenance (eg new lamp)
• integration settings
• presence of unexpected impurities
• poor initial resolution

System Suitability Criteria

Confidence in results - quantifying accuracy and precision

Use of dilution factors