Highlights:

• Columns for two-dimensional chromatography were compared to maximise orthogonality.
• Simulation software was employed to rapidly optimise 2D-HPLC operating conditions.
• 2 Optimisation protocols were compared to find the best 2D-HPLC column combination.
• Both protocols were proven to be effective at predicting the final orthogonality.
• The operating conditions were adjusted with DryLab and the simulated chromatograms were compared to the real runs.

Highlights:

• Pemetrexed sodium purity methods were developed and validated.
• Information and structure of 13 main impurities for pemetrexed sodium are provided.
• Conditions for the system suitability solutions in situ preparation are described.
• DryLab software tool was used to provide efficiency.
• The system suitability assures the main impurities resolution and identification.
• Relative response factors were determined using HPLC-UV in tandem with CAD or in combination with NMR.

Gas phase emission samples of carbonyl compounds (CCs) were collected from a research ship diesel engine at Rostock University, Germany. The ship engine was operated using two different types of fuels, heavy fuel oil (HFO) and diesel fuel (DF). Sampling of CCs was performed from diluted exhaust using cartridges and impingers. Both sampling methods involved the derivatization of CCs with 2,4-Dinitrophenylhydrazine (DNPH). The CCs-hydrazone derivatives were analyzed by two analytical techniques: High Performance Liquid Chromatography–Diode Array Detector (HPLC–DAD) and Gas Chromatography–Selective Ion Monitoring–Mass Spectrometry (GC–SIM–MS). Analysis of DNPH cartridges by GC–SIM–MS method has resulted in the identification of 19 CCs in both fuel operations. These CCs include ten aliphatic aldehydes (formaldehyde, acetaldehyde, propanal, isobutanal, butanal, isopentanal, pentanal, hexanal, octanal, nonanal), three unsaturated aldehydes (acrolein, methacrolein, crotonaldehyde), three aromatic aldehyde (benzaldehyde, p-tolualdehyde, m,o-molualdehyde), two ketones (acetone, butanone) and one heterocyclic aldehyde (furfural). In general, all CCs under investigation were detected with higher emission factors in HFO than DF. The total carbonyl emission factor was determined and found to be 6700 and 2300 μg kWh−1 for the operation with HFO and DF respectively. Formaldehyde and acetaldehyde were found to be the dominant carbonyls in the gas phase of ship engine emission. Formaldehyde emissions factor varied from 3870 μg kWh−1 in HFO operation to 1540 μg kWh−1 in DF operation, which is 4–30 times higher than those of other carbonyls. Emission profile contribution of CCs showed also a different pattern between HFO and DF operation. The contribution of formaldehyde was found to be 58% of the emission profile of HFO and about 67% of the emission profile of DF. Acetaldehyde showed opposite behavior with higher contribution of 16% in HFO compared to 11% for DF. Heavier carbonyls (more than two carbon atoms) showed also more contribution in the emission profile of the HFO fuel (26%) than in DF (22%).

Highlights:

• DryLab employs to find the optimum time of a simple (or segmented) gradient, yielding best resolution of a particular sample.
• Short silica-based monolithic columns can be used with fast 1 min- gradients up to 5 mL/min.
• Isocratic retention parameters were used for prediction and modeling gradient chromatograms.
• The gradient range was optimized for maximum peak capacities within a fixed gradient time.

Highlights:

• A suitable chromatographic system has to be employed to take the full benefits of modern LC columns.
• Extra-column band broadening and gradient delay volume have to be minimized.
• The upper pressure limit of UHPLC systems is less critical in the case of fast-LC separations.
• Acquisition rate is sufficient with spectroscopic detectors but much more critical with MS devices.
• During the last few years, column technology has evolved faster than instrumentation.