| <\/td> | HPLC<\/strong>-MS\/MS with fully porous<\/strong> column<\/td>| HPLC<\/strong>-MS\/MS with Raptor ARC-18 Core-Shell<\/strong> Column<\/td> | UHPLC<\/strong>-MS\/MS with fully porous<\/strong> column<\/td> | UHPLC<\/strong>\/MS with Raptor ARC-18 Core-Shell<\/strong> Column<\/td><\/tr> | Column Length [mm]<\/td> | 150<\/td> | 100<\/td> | 100<\/td> | 100<\/td><\/tr> | ID [mm]<\/td> | 2.1<\/td> | 2.1<\/td> | 2.1<\/td> | 2.1<\/td><\/tr> | Particle Size [\u03bcm]<\/strong><\/td> | 5<\/strong><\/td> | 2.7<\/strong><\/td> | 1.7<\/strong><\/td> | 2.7<\/strong><\/td><\/tr> | Temperature [\u00b0C]<\/td> | 25<\/td> | 25<\/td> | 45<\/td> | 30<\/td><\/tr> | Mobile Phase A<\/td> | A: 90% water, | 10% methanol, 5mM buffer *<\/td> A: 90% water, | 10% methanol, 5mM buffer *<\/td> A: 90% water, | 10% methanol, 10mM buffer *<\/td> A: 90% water, | 10% methanol, 10mM buffer *<\/td><\/tr> Mobile Phase B<\/td> | B: 100% methanol, | 5mM buffer *<\/td> B: 100% methanol, | 5mM buffer *<\/td> B: 100% methanol, | 10mM buffer *<\/td> B: 100% methanol, | 10mM buffer *<\/td><\/tr> Gradient **<\/td> | 0 – 89% B<\/td> | 0 – 89% B<\/td> | 27 – 100% B<\/td> | 15 – 100% B<\/td><\/tr> | Flow [mL\/min]<\/strong><\/td> | 0.3<\/strong><\/td> | 0.3<\/strong><\/td> | 0.25<\/strong><\/td> | 0.4<\/strong><\/td><\/tr> | Pressure [bar]<\/strong><\/td> | 150 – 350<\/strong><\/td> | 150 – 300<\/strong><\/td> | 450 – 570<\/strong><\/td> | 250 – 350<\/strong><\/td><\/tr> | Injection Volume [\u03bcL]<\/td> | 50<\/td> | 50<\/td> | 100<\/td> | 100<\/td><\/tr> | Run time (until the end of the separation) [min]<\/td> | 11.4<\/td> | 3.3<\/td> | 13.5<\/td> | 7.8<\/td><\/tr> | Total Cycle Time (until the next injection) [min]<\/strong><\/td> | 19.5<\/strong><\/td> | 10<\/strong><\/td> | 19.5<\/strong><\/td> | 10.5<\/strong><\/td><\/tr> | Advantages by using a Raptor ARC-18 Core-Shell Column<\/mark><\/strong><\/td> | <\/td> | Sharper peaks, better sensitivity, shorter analysis time<\/mark><\/strong><\/td> | <\/td> | Same separation efficiency, but longer column life time, lower pressure, shorter analysis time<\/mark><\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n | * Buffer = ammonium formate; \u200b** Gradient details on request<\/p>\n\n\n\n So far only a 0.2 \u00b5m precolumn filter could be used in front of the column for both instrument types. Using a guard column for better protection in case of waste water samples was not possible, because the pressures were already close to the limits of the systems (400 and 600 bar). Whereas the Raptor column could be used with a corresponding guard column due to the lower pressures achieved within the final method. By the way, Raptor 2.7 \u00b5m columns can also be used up to 600 bar in continuous operation if needed.<\/p>\n\n\n\n UHPLC with particles < 2 \u00b5m can certainly be the ultimate solution, but the success strongly depends on the cleanliness of the injected samples or extracts. The smaller the particle diameter, the smaller the interstitial spaces in the column, the higher the risk of clogging. Working with < 2 \u00b5m particles can be a challenge in routine analysis with varying sample types. Often laborious sample preparation is required, or the column has to be replaced frequently.<\/p>\n\n\n\n For this reason, Raptor 2.7 \u00b5m core-shell particles are a very good alternative to < 2 \u00b5m fully porous particles: the pressure and robustness is comparable to 3 \u00b5m columns, but as a result of the special particle design, their separation performance is comparable to < 2 \u00b5m fully porous particles.<\/p>\n\n\n\n Particularly important in such multi-methods is the balanced distribution of the analytes over the entire run time in order to achieve optimum sensitivity in MS. If too many compounds elute simultaneously, the sampling time per analyte in MRM mode becomes too short, which reduces sensitivity. The “balanced retention profile” of the Raptor ARC-18 phase fulfills this requirement very well (Figure 1).<\/p>\n\n\n Figure 1:<\/strong> LC-MS\/MS run of 130 pesticides on a Raptor ARC-18 core-shell column.<\/div> \n\n ![\"\"](\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-customer-application-optimization-of-a-real-pesticide-method-for-routine-analysis-faster-and-more-sensitive-on-hplc-more-robust-on-uhplc-01-1024x599.png\" "\\"-\\"") <\/figure>\n\n<\/div><\/div><\/div>\n\n\n<\/div>\n\n\n\n The robustness and stability of Raptor ARC-18 core-shell columns is shown in the following comparison (Figures 2 and 3): Four compounds were selected as examples, which elute in the early and late eluting areas of the chromatogram. All peaks show excellent retention time stability and consistent symmetrical peak shape even after 5000 injections.<\/p>\n\n\n Figure 2:<\/strong> Desisopropylatrazine, Fenuron, AIPA (anthranilic acid isopropylamide), and Diazinon on a new Raptor ARC-18 column<\/strong>.<\/div> \n\n ![\"\"](\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-customer-application-optimization-of-a-real-pesticide-method-for-routine-analysis-faster-and-more-sensitive-on-hplc-more-robust-on-uhplc-02-1024x605.png\" "\\"-\\"") <\/figure>\n\n<\/div><\/div><\/div>\n\n\n<\/div>\n\n\n Figure 3:<\/strong> Desisopropylatrazine, Fenuron, AIPA (anthranilic acid isopropylamide), and Diazinon on Raptor ARC-18 after about 5.000 injections<\/strong> (a wide variety of water samples, from ultrapure water to highly contaminated waste water) \u2014 excellent retention time stability and consistent symmetrical peak shape.<\/div> \n\n ![\"\"](\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-customer-application-optimization-of-a-real-pesticide-method-for-routine-analysis-faster-and-more-sensitive-on-hplc-more-robust-on-uhplc-03-1024x606.png\" "\\"-\\"") <\/figure>\n\n<\/div><\/div><\/div>\n\n\n<\/div>\n\n\n\n List of Components<\/h2>\n\n\n\n |