![\"\"](\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-discovering-analyte-breakdown-on-column-01-1-1024x768.png\" "\\"-\\"")
<\/figure>\n<\/div>\n\n\nFigure 1:<\/strong> On-column breakdown can be observed for the late eluting nitrosamine compounds as indicated by the foot at the leading edge of the peak.<\/p>\n\n\n\n I attempted to translate the simulation to a column with the same phase but with a thicker film. Since the Rxi-624Sil MS and Rxi-1301Sil MS are the same stationary phase I modeled a run with the Rxi-1301Sil MS Library using the column dimensions of an Rxi-624 Sil MS. As I ran the conditions provided by EZGC we noticed a strange rise of the baseline.<\/p>\n\n\n Figure 2:<\/strong> Rise in the baseline is observed which is most likely caused by analyte breakdown on-column. Breakdown components remain in the stationary phase and are observed as carryover.<\/p>\n\n\n\n One of my colleagues immediately suggested that the nitrosamines could break down as a function of elution temperature. In order to test this theory I prepared three different run conditions with different elution temperatures for the late eluting nitrosamines on the Rxi-624 Sil MS:<\/p>\n\n\n\n Figure 3:<\/strong> Adjusting the final hold changes the elution temperature of the last three compounds. If the compound response drops as elution temperature increases it will support our theory of on-column breakdown.<\/p>\n\n\n\n These are the compounds I used (sorted by elution order):<\/p>\n\n\n\n Figure 4:<\/strong> List of nitrosamines found in the chromatogram where the last three compounds are labeled as 1 2 and 3.<\/p>\n\n\n Figure 5:<\/strong> Three chromatograms illustrating the three different programs with increasing elution temperature of the last three nitrosamines. Notice the significant increase in breakdown.<\/p>\n\n\n\n I labeled the last three peaks; the ones that break down appear to have the most activity on-column. Thanks to the MS I was still able to determine the retention times and it became evident that the breakdown increases with higher elution temperature. Was this a general problem with these compounds on this phase or was this specific to the Restek column?<\/p>\n\n\n Figure 6:<\/strong> Chromatograms with three different oven conditions. The last three nitrosamines have increasing elution temperatures from top to bottom. These chromatograms were performed on a competitor column to verify the on-column breakdown is most likely related to the cyano stationary phase and not specific to a manufacturer.<\/p>\n\n\n\n I completed my winter internship at Restek and my main task was to expand the Pro-EZGC libraries. So I created a library for Nitrosamines on the Rxi-1301Sil MS and while acquiring data we noticed a foot on a couple of my peaks.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kadence_starter_templates_imported_post":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"footnotes":""},"categories":[792],"tags":[],"industries-application":[],"post-badge":[],"resource-type":[562],"product-library":[],"resource-technique":[2324],"hf_cat_post":[],"ppma_author":[768],"class_list":["post-93918","post","type-post","status-publish","format-standard","hentry","category-blogs-de","resource-type-chromatography-fundamentals","resource-technique-gaschromatographie-gc"],"acf":[],"taxonomy_info":{"category":[{"value":792,"label":"Blogs"}],"resource-type":[{"value":562,"label":"Chromatography Fundamentals"}],"resource-technique":[{"value":2324,"label":"Gaschromatographie (GC)"}]},"featured_image_src_large":false,"author_info":{"display_name":"Patrick Gallagher","author_link":"https:\/\/discover.restek.com\/de\/author\/patrick-gallagherrestek-com\/"},"comment_info":0,"category_info":[{"term_id":792,"name":"Blogs","slug":"blogs-de","term_group":0,"term_taxonomy_id":792,"taxonomy":"category","description":"","parent":0,"count":442,"filter":"raw","cat_ID":792,"category_count":442,"category_description":"","cat_name":"Blogs","category_nicename":"blogs-de","category_parent":0}],"tag_info":false,"authors":[{"term_id":768,"user_id":0,"is_guest":1,"slug":"yannic-schneck","display_name":"Yannic Schneck","avatar_url":"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&r=g","0":null,"1":"","2":"","3":"","4":"","5":"","6":"","7":"","8":""}],"_links":{"self":[{"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/posts\/93918","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/comments?post=93918"}],"version-history":[{"count":5,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/posts\/93918\/revisions"}],"predecessor-version":[{"id":93927,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/posts\/93918\/revisions\/93927"}],"wp:attachment":[{"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/media?parent=93918"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/categories?post=93918"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/tags?post=93918"},{"taxonomy":"industries-application","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/industries-application?post=93918"},{"taxonomy":"post-badge","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/post-badge?post=93918"},{"taxonomy":"resource-type","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/resource-type?post=93918"},{"taxonomy":"product-library","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/product-library?post=93918"},{"taxonomy":"resource-technique","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/resource-technique?post=93918"},{"taxonomy":"hf_cat_post","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/hf_cat_post?post=93918"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/ppma_author?post=93918"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-discovering-analyte-breakdown-on-column-02-1-1024x768.png\" "\\"-\\"")
<\/figure>\n<\/div>\n\n\nLow Temp<\/th> Heatrate<\/th> Temp.<\/th> Holdtime<\/th><\/tr><\/thead> Start<\/td> <\/td> 35 \u00b0C<\/td> 1 min.<\/td><\/tr> Ramp<\/td> 20 \u00b0C\/min.<\/td> 225 \u00b0C<\/td> 18 min.<\/td><\/tr> Constant Flow<\/td> Flowrate: 1.4 mL\/min.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n Middle Temp<\/th> Heatrate<\/th> Temp.<\/th> Holdtime<\/th><\/tr><\/thead> Start<\/td> <\/td> 35 \u00b0C<\/td> 1 min.<\/td><\/tr> Ramp<\/td> 20 \u00b0C\/min.<\/td> 250 \u00b0C<\/td> 9 min.<\/td><\/tr> Constant Flow<\/td> Flowrate: 1.4 mL\/min.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n High Temp<\/th> Heatrate<\/th> Temp.<\/th> Holdtime<\/th><\/tr><\/thead> Start<\/td> <\/td> 35 \u00b0C<\/td> 1 min.<\/td><\/tr> Ramp<\/td> 20 \u00b0C\/min.<\/td> 280 \u00b0C<\/td> 4 min.<\/td><\/tr> Constant Flow<\/td> Flowrate: 1.4 mL\/min.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n Name<\/th> Abbreviation<\/th> <\/th><\/tr><\/thead> N-Nitrosodimethylamine<\/td> NDMA<\/td> <\/td><\/tr> N-Nitrosomethylethylamine<\/td> NMEA<\/td> <\/td><\/tr> N-Nitrosodiethylamine<\/td> NDEA<\/td> <\/td><\/tr> N-Nitrosodipropylamine<\/td> NDPA<\/td> <\/td><\/tr> N-Nitrosomorpholine<\/td> NMOR<\/td> <\/td><\/tr> N-Nitrosopyrrolidine<\/td> NPYR<\/td> <\/td><\/tr> N-Nitrosopiperidine<\/td> NPIP<\/td> <\/td><\/tr> N-Nitrosodibutylamine<\/td> NDBA<\/td> <\/td><\/tr> N-Nitrosodiethanolamine<\/td> NDELA<\/td> <\/td><\/tr> N-Nitrosodiphenylamine<\/td> NDPhA<\/td> <\/td><\/tr> N-NitrosoNorNikotine<\/td> NNN<\/td> <\/td><\/tr> N-Nitrosodibenylamine<\/td> NDBzA<\/td> Peak Labeled as 1<\/td><\/tr> N-Nikotin-NitrosaminoKetone<\/td> NNK<\/td> Peak Labeled as 2<\/td><\/tr> N-Nitrosodi-iso-propanolamine<\/td> NDIPLA<\/td> Peak Labeled as 3<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n ![\"\"](\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-discovering-analyte-breakdown-on-column-05-1-1024x768.png\" "\\"-\\"")
<\/figure>\n<\/div>\n\n\n![\"\"](\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-discovering-analyte-breakdown-on-column-06-1-1024x768.png\" "\\"-\\"")
<\/figure>\n<\/div>\n\n\n