System Suitability

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System Suitability

System SuitabilityThe checking of a system, before or during analysis of unknowns, to insure system performance.Plate Count, Tailing, Resolution, Capacity FactorDetermination of reproducibility (%RSD)

System Suitability "Sample"A mixture of main components and expected by-products utilized to determine system suitability

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System Suitability

Reproducibility

Separation Review

System Troubleshooting

SystemSuitability

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ReproducibilityPrecision

The measure of the degree of agreement among test results when the method is applied repeatedly to multiple samplings of a homogeneous sampleExpressed as %RSD for a statistically significant number of samples

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Definition of SpecificitySpecificity (Selectivity)

The ability to measure accurately and specifically the analyte in the presence of components that may be expected to be present in the matrixThe degree of interference

Active IngredientsExcipientsImpuritiesDegradation ProductsPlacebo Ingredients

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Specificity (Selectivity)

SeparationResolution

Determination of separation between peaks

Plate CountDetermination of a systems efficiency

Tailing FactorCalculation referencing peak shape

PDAPurity AnglePurity Plots

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Resolution RR = 1 2% Overlap 4σR = 1.5 baseline separation 6σ

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Resolution R

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1 .0 1 .2 5

9 9 .4

9 8

9 5

0 .8

8 88 3

R s = 0 .40 .5 0 .6

0 .7

9 2

The value of 1.5 or more, indicates that peaks are separated through base line.

Resolution R

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Capacity factor k´

mobilephasestat

AmountAmount

VVKk

m

s.´ ==

K = Cs

Cmsubstitute

=Ms Vm

Mm Vs

k´=vr-v0v0 =

tr-t0t0

Capacity Factor describes the migration rate of an analyte through a column

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N = Theoretical PlatesA Measure of Efficiency

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EfficiencyPeak broadening during separation

minutes0 126

W = 0,55 min

10,2 min

N = 16 (tr/w)2 = 16 *(10,2 / 0,55)2= 5500

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Calculation of Column Efficiency5σ Method

7018.=RV

plates 8240

1.0318.7025N

2

5

=

⎥⎦⎤

⎢⎣⎡=

1.03W =

height4.4%

height4.4%

plates 3334

N5

=

⎥⎦⎤

⎢⎣⎡=σ

2

441631625

..

6316.=RV

1.44W =

Good Column Bad Column

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• Factors that will influence the efficiency, N :– Flow rate (linear velocity)– Column length– Particle size– Particle size distribution– Porosity– Injection volume– Solvent viscosity– Column temperature– Particle shape (spherical versus irregular)– Retention– Extra column band spreading (in tubing and

instruments)

Optimizing efficiency, N

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Asymmetry Factor

ABAs =

4.4%

A B

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FDA Guidelines for System Suitability

Parameters Guidelines

Repeatability of peak response

1.0% for 5 replicates

Resolution Minimum 2.0

Tailing factor Less then or equal to 1.0

Column efficiency Greater then 2000 (plate count)

Capacity factor Greater then 2

Slide Number 1Slide Number 2Slide Number 3Slide Number 4Definition of SpecificitySpecificity (Selectivity)Slide Number 7Slide Number 8Slide Number 9Slide Number 10Slide Number 11Slide Number 12Slide Number 13Slide Number 14Slide Number 15Slide Number 16