Application of an in-house packed octadecylsilica-functionalized graphene oxide column for capillary liquid chromatography analysis of hormones in urine samples

Applicability and Limitations of a Capillary-LC Column-Switching System Using Hybrid Graphene-Based Stationary Phases

“…Accuracy and precision are other critical factors in quantitative analysis. For this work, the acceptance criteria were accuracy between 70–110% and precision with % RSD <20%; these values were based on previous work using graphene-based extraction or analytical columns [ 33 , 41 ]. Table 1 presents the accuracy and precision data obtained.…”

“…However, the peak capacity observed in this study was lower than that reported in the literature for columns containing the same phase (SiGO-C18ec particles of 10 µm diameter). Notably, for hormone separation, a peak capacity of around 27 peaks in 15 min was reported [ 41 ], while for the separation of multiclass analytes, the reported peak capacity was 14 peaks in 15 min [ 42 ]. A comparison with other graphene-based stationary phases revealed similar outcomes.…”

“…Deionized ultrapure water (H 2 O) was produced in the lab by a Milli-Q ® Millipore system (Burlington, NJ, USA). The SiGO and SiGO-C18ec fully porous particles (FPPs) were produced as described by Maciel et al [ 41 ]. The C18 column packed with 1.9 µm superficially porous particles (SPPs) was a Hypersil GOLD 50 × 2.1 mm (Thermo Electronic Corporation, San Jose, CA, USA).…”

“…Graphene sheets fixed to silica particles [ 35 , 36 ], graphene oxide sheets fixed to silica particles functionalized with C18 [ 37 , 38 ], graphene sheets fixed to silica particles modified with gold nanoparticles [ 39 ], and cellulose-coated reduced oxide sheets fixed to silica particles [ 40 ] are examples of some materials that have been applied as stationary phases in liquid chromatography. Columns packed with the SiGO-C18ec phase have been successfully used in quantitative analyses of hormones in urine samples [ 41 ]. A recent study compared a SiGO-C18ec with a commercial C18 column, both packed capillary LC columns operating in reverse-phase LC [ 42 ].…”

Recent Trends in Graphene-Based Sorbents for LC Analysis of Food and Environmental Water Samples

“…These applications include the use of techniques such as stir bar sorptive extraction (SBSE) [ 25 , 26 ], dispersive solid phase extraction (d-SPME) [ 27 , 28 ], fiber solid phase microextraction (Fiber-SPME) [ 29 , 30 ], in-tube solid-phase microextraction (IT-SPME), and others [ 2 , 24 ] in sample preparation methods. Additionally, graphene-based materials have been explored as packing materials for analytical columns in LC, including using graphene oxide (GO) fixed to silica particles functionalized with C18, graphene (G) fixed to silica particles modified with gold nanoparticles, and reduced graphene oxide (rGO) coated with cellulose fixed to silica particles [ 31 , 32 , 33 , 34 ]. The variety of analytes that can be analyzed using these phases is as diverse as applying graphene-based sorbents in analytical techniques.…”