Carbon Molecular Sieves and Spherical Graphitized Polymer Carbons for Sample Preparation Processes and Bulk Scale Purification Processes

Transcription

1 Carbon Molecular Sieves and Spherical Graphitized Polymer Carbons for Sample Preparation Processes and Bulk Scale Purification Processes William R. Betz, Michael J. Keeler, Jay M. Jones, Wendy S. Roe, and Michael D. Buchanan Supelco, Div. of Sigma-Aldrich Bellefonte, PA USA T sigma-aldrich.com/analytical 2014 Sigma-Aldrich Co. All rights reserved.

2 Introduction High purity, spherical graphitized polymer carbons (SGPC) and spherical, high purity carbon molecular sieves (CMS) have been synthesized for use in sample preparation processes and bulk-scale purification processes. The use of new SGPC and CMS particles in packed bed systems and coated devices provides a recent advancement in these technologies. Graphitized carbon blacks (granular) also provide recent advances in these technologies. These carbons have also found uses in bulk-scale purification processes. 2

3 Materials and Methods Spherical CMS particles have been synthesized for sample preparation analyses and bulk scale purification processes. For example, a 2.0 μm CMS with a large microporous regime allowed for the preparation of coated surfaces for the extraction and subsequent analyses of small molecular sized, airborne contaminants. These CMS particles with sub-10 µm particle sizes have been bonded to glass, metal and plastic substrates using patented, proprietary adhesives (1,2). These applications focused also on a range of analytes from light gases to the semi-volatiles in aqueous environments. The surface chemistries of several 50 μm and 600 μm CMS particles have been applied to bulk extraction processes. SGPC particles have also been synthesized which possess a wide range of textural properties and surface chemistries. For example, 50 μm monodispersed SGPC particles possessing surface areas of 20 m 2 /g and 100 m 2 /g (3) have been effective in improving the adsorption and flow characteristics of a solid phase extraction (SPE) device for planar pesticides, pesticide, insecticide and herbicide analyses. SGPC particles with sub-10 µm particle sizes have also been bonded to glass, metal and plastic substrates using patented, proprietary adhesives for sample preparation applications. 3

4 Materials and Methods (contd.) Spherical CMS and SGPC particles have also been synthesized for bulk scale purification processes such as pharmaceutical compound purification. The tailoring of the carbon pore structure and surface chemistry (range from ph = ) allow for selective purification processes. 4

5 Results and Discussion Sample Preparation Data Figure 1 provides a low resolution SEM photograph of the 20 m 2 /g SGPC for planar pesticide analyses using dispersive SPE technology. The recovery of the planar pesticides has been an inherent 30 year problem for the US EPA, with recoveries less than 15%. This carbon provides a greater than 80% recovery for the planar pesticides, including hexachlorobenzene. Figure μm SGPC for Planar Pesticides (20 m 2 /g) 5

6 Sample Preparation Data Figure 2 illustrates a 100 m 2 /g SGPC with a 50 µm monodispersed particle size distribution. This SGPC has been effective in improving the adsorption and flow characteristics of a solid phase extraction (SPE) device for pesticide, insecticide and herbicide analyses. A low resolution SEM photograph of the SGPC carbon is presented. Figure μm SGPC for Pesticides (100 m 2 /g) 6

7 Sample Preparation Data Amorphous CMS carbons with surface areas of m 2 /g have been effective for use in SPE applications focused on small, polar molecules such as small, polar pesticides. Figure 3 illustrates one of these μm CMS carbons. Figures 4-6 illustrate 2 additional ultra-microporous CMS carbons for use in small molecule adsorption processes. These carbons are used for small polar molecules (e.g., Propylene Glycol) extracted from aqueous matrices, and small gas phase molecules such as methane, ethane, propyne, propylene and propane. Figure μm CMS Carbon (1300 m 2 /g) 7

8 Sample Preparation Data Figure μm CMS Carbon (1004 m 2 /g) 8

9 Sample Preparation Data Figure μm CMS Carbon (829 m 2 /g) 9

10 Sample Preparation Data Figure 6. DFT Overlay of μm CMS Carbons 10

11 Sample Preparation Data A second example is a family of these carbons, with surface areas ranging from one to two hundred meters per gram. SGPC particles with sub-10 µm particle sizes have been bonded to glass, metal and plastic substrates using patented, proprietary adhesives (1,2), as illustrated in Figures 7-9. These coated devices are used for air sampling of chemical and biological warfare agents. 11

12 Sample Preparation Data Figure 7. Nano-GPC Coated Screen 2 patented adhesives (Siloxane-1997 and Silazane-2011) Figure 9. Nano-GCB Figure 8. Spherical, sub-10 µm CMS 12

13 Bulk-Scale Purification Data Spherical CMS and GPC particles have also been synthesized for bulk-scale purification processes such as pharmaceutical impurities removal. Both cartridge and bulk-addition processes have been evaluated for effectiveness. Also, the tailoring of the carbon pore structure and surface chemistry (range from ph = ) allow for selective purification processes. Table 1 provides a list of the bulk-scale carbons. 13

14 Table 1. A List of High Purity Scalable Carbons Carbon Name Carbon Description Particle Shape BET Surface Area (m 2 /g) Carboxen 1003 Carbon Molecular Sieve Spherical 1000 Carboxen 1005 Carbon Molecular Sieve Spherical 1150 Carboxen 1030 Carbon Molecular Sieve Spherical 700 Carboxen 1032 Carbon Molecular Sieve Spherical 820 Carboxen 1033 Carbon Molecular Sieve Spherical 430 Carboxen 1034 Carbon Molecular Sieve Spherical 1260 Carboxen 563 Carbon Molecular Sieve Spherical 510 Carboxen 564 Carbon Molecular Sieve Spherical 400 Carboxen 569 Carbon Molecular Sieve Spherical 485 Carboxen 572 Carbon Molecular Sieve Spherical 1100 Graphsphere 2017 Spherical Graphitized Polymer Carbon Spherical 61 Carbotrap B Graphitized Carbon Black Granular 100 Carbotrap C Graphitized Carbon Black Granular 10 Carbotrap F Graphitized Carbon Black Granular 5 Carbotrap X Graphitized Carbon Black Granular 240 Carbotrap Y Graphitized Carbon Black Granular 24 14

15 Bulk-Scale Purification Data The surface chemistries of the carbon molecular sieves can be adjusted to provide a range of ph and meq/g values. Table 2 provides an example of the ph ranges of these carbons. 15

16 Table 2. A List of High Purity Scalable Carbons with ph Values Highlighted Carbon Name Carbon Description Particle Shape BET Surface Area (m 2 /g) Carboxen 1003 Carbon Molecular Sieve Spherical 1000 Carboxen 1005 Carbon Molecular Sieve Spherical 1150 Carboxen 1030 Carbon Molecular Sieve Spherical 700 ph Specific Carboxen 1032 Carbon Molecular Sieve Spherical Carboxen 1033 Carbon Molecular Sieve Spherical Carboxen 1034 Carbon Molecular Sieve Spherical Carboxen 563 Carbon Molecular Sieve Spherical 510 Carboxen 564 Carbon Molecular Sieve Spherical 400 Carboxen 569 Carbon Molecular Sieve Spherical 485 Carboxen 572 Carbon Molecular Sieve Spherical 1100 Graphsphere Spherical Graphitized 2017 Polymer Carbon Spherical 61 Carbotrap B Graphitized Carbon Black Granular 100 Carbotrap C Graphitized Carbon Black Granular 10 Carbotrap F Graphitized Carbon Black Granular 5 Carbotrap X Graphitized Carbon Black Granular 240 Carbotrap Y Graphitized Carbon Black Granular 24 16

17 Bulk-Scale Purification Data An application example of a CMS used in a cartridge for removal of impurities present in methanol is provided below in Figures

18 Figures GC-MS Data Illustrating Impurities Removal From Methanol Abundance 0.00E E+06 C11 hydrocarbon Fatty acid methyl esters (C16-C18) Time (min) Bottled Methanol (Organic Impurities) Abundance 0.00E E+06 C11 hydrocarbon Fatty acid methyl esters (C16-C18) Time (min) Bulk Tank Methanol (Organic Impurities) Abundance 0.00E E Time (min) Carbon Treated Bulk Tank Methanol (100 Gallons Methanol; 300 g Carboxen-1005 Cartridge) 18

19 Conclusions High purity, spherical graphitized polymer carbons (SGPC), spherical, high purity carbon molecular sieves (CMS) and granular high purity, nanographitized carbon blacks (GCB) have been synthesized for use in chromatographic, sample preparation processes and bulk extraction processes. The use of carbons in gas and liquid chromatography as well as samples preparation applications has been realized for several decades. Continued advancements in the carbon synthesis technology have led to improving these applications, specifically the detection levels required for effective trace-level analyses. 19

20 References 1. Betz, W. and J. Desorcie, Nucleophilic Bodies Bonded to Siloxane and Use Thereof for Separations from Sample Matrices, Japan Patents JP , JP , US Patents US , US , US , US , US Betz, W. and C. Linton, Polysilazane Thermosetting Polymers for Use in Chromatographic Systems and Applications, US , US , US , US Webb, P.A. and Orr, C., Analytical Methods in Fine Particle Technology. Micromeritics, Norcross, GA, Carboxen and Carbopack are registered trademarks of Sigma-Aldrich Co. LLC. 20