U-HPLC

The required instrument hardware was only recently commercialized this may explain why the IPC literature concerning U-HPLC is very limited and contemporary. For example, ion-pair U-HPLC coupled with electrospray time-of-flight mass spectrometry played a crucial role in development of rapid and sensitive analytical... 

Neue, U. HPLC Columns Theory, Technology, and Practice, Wiley New York, 1997. 

Pump type and mixing volume To some degree, all modern (U)HPLC pumps allow you to realize an overall GDV of 250 )il or less - getting much below 100 pi of GDV, however, is still a major challenge. Due to their operation principle, high-pressure gradient (HPG)pumps have an inherent advantage with respect to GDV... 

Haschke, M. Zhang, Y.L. Kahle, C. Klawitter, J. Korecka, M. Shaw, L.M. Christians, U. HPLC atmospheric pressure chemical ionization MS/MS for quantification of 15-F2t-isoprostane inhuman urine and plasma. Clin. Chem. 2007, 53 (3), 489 97. 

More recently, ultra-high-performance liquid chromatography (u-HPLC) method coupled with MS has been adopted in many areas of food and biological analysis due to its rapid analysis and remarkabl separation capacity [103,104], u-HPLC method is economical and environmentally friendly due to its extremely rapid analysis and the consumption of solvent for the mobile phase can be reduced 5- to 10-fold compared to the conventional HPLC method [9,105]. 

Stage that requires high efficiency as well as speed, due to the complexity of the sample matrix, and hence it is particularly challenging to achieve the goals. Therefore, the development of a rapid, sensitive, and reproducible method has been required for separation and determination of capsaicinoid compounds. The addition of ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) method fulfilled these aforementioned demands and showed some complementary advantages to the conventional HPLC-MS, u-HPLC methods in terms of shorter analysis times, low sample volume, and much improved sensitivity [71]. Therefore, nowadays this UPLC-MS technique is routinely performed in pharmaceutical industries and related contract research institutes, laboratories concerned with biochemistry, biotechnology, environmental analysis, natural product research, and several other research fields. The UPLC-MS method has successfully been applied for the determination of n-DHC, C, DHC, h-C, and h-DHC present in the varieties of hot peppers [71]. 

Wille K, Kiebooms JAL, Claessens M, Rappe K, Vanden Bussche J, Noppe H, et al. Development of analytical strategies using U-HPLC-MS/MS and LC-ToF-MS for the quantification of micropollutants in marine organisms. Anal Bioanal Chem 2011 400(5) 1459-72. 

Like GC, HPLC has progressed enormously in terms of efficiency and analysis time to lead to the U-HPLC or Ultra Performance Liquid Chromatography (UPLC). This allows, by reducing the diameters of stationary-phase particles, for larger flow ranges. It is thus possible to increase the flow, and, therefore, the speed of analysis, without altering the chromatographic separation. Today, this method has become the standard for metabolomic analyses. 

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