{"id":51708,"date":"2014-12-01T14:30:00","date_gmt":"2014-12-01T14:30:00","guid":{"rendered":"https:\/\/discover.restek.com\/uncategorized\/how-dirty-are-you-part-4manual-syringe-rinsingthe-question\/"},"modified":"2026-01-28T15:54:12","modified_gmt":"2026-01-28T15:54:12","slug":"how-dirty-are-you-part-4manual-syringe-rinsingthe-question","status":"publish","type":"post","link":"https:\/\/discover.restek.com\/de\/blogs\/gnbl4695\/how-dirty-are-you-part-4manual-syringe-rinsingthe-question","title":{"rendered":"How Dirty Are You? Part 4\u2026Manual Syringe Rinsing\u2026The Question"},"content":{"rendered":"\n
\"image<\/figure>\n\n\n\n

I don’t even want to guess how many times you would need to rinse this syringe before removing all traces of reanimation “reagent”<\/a>…<\/p>\n\n\n\n

This How Dirty Are You?<\/em><\/a> blog should really be credited with inspiring the entire project. I was discussing the number of times I rinse my syringes with a colleague, Michelle Misselwitz, a few years ago. We were working in the same hood and I noticed that she rinsed her syringe a lot\u2026I do too. I was even reminded of my rather obsessive rinsing at Thanksgiving this year. I was washing a few dirty dishes by hand and my mother mentioned that I was rinsing them a lot\u2026and that my grandmother would have been upset because I was wasting so much water\u2026but \u201cWhat about the soap residue?\u201d I said.<\/p>\n\n\n\n

Over the years, I have been told different things about the number of times a syringe should be rinsed to prevent carryover\/contamination\u2026and I have been asked the same question many times. I was told early in my lab career that 7 was the magic number\u2026so just to be sure, I got in the habit of using 10 rinses.<\/p>\n\n\n\n

What We Did<\/h2>\n\n\n\n

There are a lot of variables to consider\u2026sample matrix, compound concentration, sample solvent, rinse solvent(s), rinse volume etc. But to keep things simple, we used a hydrocarbon standard at a high level and rinsed with the same solvent as the sample solution, acetonitrile. We also defined the volume of a \u201crinse\u201d as 20 \u00b5L. We started the experiment with a 20 \u00b5L draw of a 500 ppm hydrocarbon standard. The hydrocarbon standard was expelled and then consecutive rinses were performed. Each rinse was tested by GC-FID.<\/p>\n\n\n\n

Sequence of manual syringe rinsing:<\/h3>\n\n\n\n
    \n
  1. 20 \u00b5L draw of a 500 ppm hydrocarbon standard and expel it<\/li>\n\n\n\n
  2. 20 \u00b5L draw of acetonitrile \u2013 eject into sample vial \u2013 test via GC-FID<\/li>\n\n\n\n
  3. Repeat step 2 many times<\/li>\n<\/ol>\n\n\n\n

    Question<\/h2>\n\n\n\n
      \n
    1. How many 20 \u00b5L acetonitrile rinses were needed to show no signal (FID)?
      (Hint: The answer is between 1 and 15…I didn’t say it was a good hint.)<\/li>\n<\/ol>\n\n\n\n

      (photo credit: http:\/\/philosophicalasides.blogspot.com)<\/p>\n\n\n\n

      <\/div>\n","protected":false},"excerpt":{"rendered":"

      Over the years, I have been told different things about the number of times a syringe should be rinsed to prevent carryover\/contamination…and I have been asked the same question many times. I was told early in my lab career that 7 was the magic number…so just to be sure, I got in the habit of using 10 rinses.<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","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":[9],"tags":[],"industries-application":[],"post-badge":[],"resource-type":[],"product-library":[],"resource-technique":[2294],"ppma_author":[594],"class_list":["post-51708","post","type-post","status-publish","format-standard","hentry","category-blogs","resource-technique-gas-chromatography-gc"],"acf":[],"taxonomy_info":{"category":[{"value":9,"label":"Blogs"}],"resource-technique":[{"value":2294,"label":"Gas Chromatography (GC)"}]},"featured_image_src_large":false,"author_info":{"display_name":"Brenda Cogan","author_link":"https:\/\/discover.restek.com\/de\/author\/brenda-coganrestek-com\/"},"comment_info":0,"category_info":[{"term_id":9,"name":"Blogs","slug":"blogs","term_group":0,"term_taxonomy_id":9,"taxonomy":"category","description":"","parent":0,"count":444,"filter":"raw","cat_ID":9,"category_count":444,"category_description":"","cat_name":"Blogs","category_nicename":"blogs","category_parent":0}],"tag_info":false,"authors":[{"term_id":594,"user_id":0,"is_guest":1,"slug":"julie-kowalski","display_name":"Julie Kowalski","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\/51708","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\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/comments?post=51708"}],"version-history":[{"count":4,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/posts\/51708\/revisions"}],"predecessor-version":[{"id":85338,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/posts\/51708\/revisions\/85338"}],"wp:attachment":[{"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/media?parent=51708"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/categories?post=51708"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/tags?post=51708"},{"taxonomy":"industries-application","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/industries-application?post=51708"},{"taxonomy":"post-badge","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/post-badge?post=51708"},{"taxonomy":"resource-type","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/resource-type?post=51708"},{"taxonomy":"product-library","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/product-library?post=51708"},{"taxonomy":"resource-technique","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/resource-technique?post=51708"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/discover.restek.com\/de\/wp-json\/wp\/v2\/ppma_author?post=51708"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}