LC Technology study plan

Define the retention factor k, selectivity α, and resolution Rs and derive how each term in the resolution equation moves when a variable changes

Calculate plate number N and plate height H from a peak width and retention time you measure or are given, and state the assumptions behind each formula

Explain the van Deemter curve in terms of eddy diffusion, longitudinal diffusion, and mass transfer, and predict which term dominates at low versus high linear velocity

Compare reversed-phase, normal-phase, ion-exchange, and HILIC retention mechanisms by the dominant interaction each relies on

Apply the gradient equation to predict how peak capacity and retention change when gradient time, flow rate, or column length is altered

Distinguish isocratic from gradient elution by when band compression occurs and which peaks are affected

Select a stationary phase (C18, C8, phenyl, mixed-mode) for a stated analyte polarity and justify the choice in two sentences

Explain peak asymmetry and tailing factor and list three chemical causes of tailing

Trace the solvent path from reservoir through degasser, pump, injector, column, and detector and name the failure mode most likely at each stage

Differentiate binary high-pressure and low-pressure gradient pumps by how the mobile phase is proportioned and mixed

Explain how a UV-Vis variable-wavelength detector and a photodiode array detector differ in data collected and when each is preferred

Describe autosampler injection modes (full loop, partial loop, needle-in-loop) and the carryover risk of each

List the maintenance interval and failure symptom for pump seals, check valves, and inline filters

Set initial method conditions from analyte pKa, logP, and UV absorbance for a stated compound set

Design a scouting gradient to locate retention and then convert to isocratic or shallow-gradient conditions

Optimize selectivity before resolution by adjusting solvent strength, pH, and organic modifier in a defined order

Explain how buffer choice and pH control ionization state and retention for ionizable analytes

Evaluate method robustness by identifying the three parameters most likely to shift retention

Select a sample preparation technique (dilute-and-shoot, protein precipitation, liquid-liquid extraction, solid-phase extraction) for a stated matrix and analyte concentration

Calculate recovery and matrix effect for a spiked sample using pre- and post-extraction spiking

Describe how injection solvent strength relative to mobile phase causes peak distortion and how to correct it

Identify the regulatory requirements that govern method validation (specificity, linearity, accuracy, precision, LOD/LOQ, robustness) for a stated context

List the safety controls for common LC solvents and buffers, including flammable solvent storage, waste segregation, and pressure-system hazards

Set integration parameters (peak width, threshold, baseline mode) and explain how each changes a reported area

Distinguish baseline-to-baseline, valley-to-valley, and tangent-skim integration for unresolved peaks and state when each is acceptable

Build a calibration curve, evaluate linearity and weighting, and calculate concentration from a peak-area ratio using an internal standard

Define LOD and LOQ by signal-to-noise and by standard deviation of response, and compare the two approaches

Identify integration and quantitation errors that would fail a data review and describe how to document a manual integration

Diagnose retention-time drift, ghost peaks, and baseline noise by ranking likely causes from most to least probable

Distinguish pump-related pressure fluctuations from column-related back-pressure increases using pressure trace behavior

Explain how a leaking check valve, worn seal, and air in the solvent line each present differently and how to confirm each

Write a systematic troubleshooting sequence for a split or fronting peak that isolates cause without replacing parts blindly

Describe a column care and storage regimen that prevents the most common degradation modes

Review all seven domains using your own notes, prioritizing the two domains with the weakest practice scores

Complete timed practice sets and record accuracy by domain to target remaining gaps

Re-derive the core separation equations from memory without reference

Summarize the regulatory and safety requirements most likely to be tested in a single reference sheet