{"id":40169,"date":"2025-07-31T13:50:47","date_gmt":"2025-07-31T11:50:47","guid":{"rendered":"https:\/\/membrapure.de\/?p=40169"},"modified":"2025-07-31T14:56:32","modified_gmt":"2025-07-31T12:56:32","slug":"technical-note-suppressor-study-with-ionus","status":"publish","type":"post","link":"https:\/\/membrapure.de\/de\/tech-note-innovation-2\/technical-note-suppressor-study-with-ionus\/","title":{"rendered":"Technical Note \u2013 Suppressor Study IONUS Ion Chromatograph"},"content":{"rendered":"\n

Our ion chromatograph<\/a> is designed with high flexibility allowing it to operate with\u00a0 common brands of chromatography columns without restriction.<\/p>\n\n\n\n

Recently, we have added a new suppressor to our product portfolio which like its predecessor operates using chemical regeneration. The following results present partially a comparative performance evaluation of various chromatography columns tested with the previous and the new suppressor with a particular focus on assessing the capabilities of the newly introduced suppressor.<\/p>\n\n\n\n

Materials and methods<\/strong><\/p>\n\n\n\n

To prepare the analytical solutions precise amounts of the target anions were weighed to produce an individual 1000 mg\/Kg standard when dissolved in ultra pure water. These known masses were then dissolved in ultrapure water (UPW) to create individual solutions of 1000 mg\/Kg concentrations.<\/p>\n\n\n\n

We used standards of 1000 ppm (Inorganic Ventures) mostly certified and based on sodium.<\/p>\n\n\n\n

Using the prepared individual 1000 mg\/Kg standards, a mixed stock working standard was prepared. The stock standard was used to produce various concentration ranges by weight to develop the calibration curve for the project. The exact mass values recorded in the laboratory worksheets can be provided upon request.<\/p>\n\n\n\n

The focus of these investigations was on the determination of inorganic anions: Fluoride, Chloride, Nitrite, Bromide, Nitrate, Phosphate, and Sulfate. We use a 1 ppm standard for Fluoride, Chloride, and Nitrate, and a 2 ppm standard for Phosphate and Sulfate.<\/p>\n\n\n\n

Operating Conditions of the Method:<\/strong><\/strong><\/p>\n\n\n\n

IC System<\/strong><\/td>IONUS Ion Chromatograph<\/strong><\/td><\/tr>
Column<\/strong><\/td>Specifications see corresponding results<\/strong><\/td><\/tr>
Eluent<\/strong><\/td>Parameters see corresponding results<\/strong><\/td><\/tr>
Suppressor<\/strong><\/td>membraPure IC Suppressor PEEK. 4.6 mm x 100 mm and membraPure IC Suppressor\u00b2 4.6 x 50 mm PEEK<\/strong><\/td><\/tr>
Regenerant<\/strong><\/td>1N Sulfuric Acid<\/strong><\/td><\/tr>
Eluent Flow Rate:<\/strong><\/td>Parameters see corresponding results<\/strong><\/strong><\/td><\/tr>
Column Temp:<\/strong><\/td>Parameters see corresponding results<\/strong><\/strong><\/td><\/tr>
Injection<\/strong><\/td>Parameters see corresponding results<\/strong><\/strong><\/td><\/tr>
Water Source<\/strong><\/td>Aquinity\u00b2 P10 Analytical                (0.055 \u00b5S\/cm. Type I)<\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

A total of two first-generation (1+2) and four next-generation suppressors (A, B, C, D) were available for the tests.  In the following, the suppressors of the first generation are referred to as Supp<\/em>, while the new generation suppressors are denoted as Supp\u00b2. Because we proved by multiple injections on multiple columns that the suppressors were reproducible not all suppressors were tested with every chromatography column in every instance.<\/p>\n\n\n\n

For each series of measurements five replicate measurements were performed and the relative standard deviation (RSD %) was calculated to assess precision and reproducibility. The results are summarized in the following table sheets. To maintain clarity chromatograms are not shown here but will be gladly provided upon request.
<\/strong><\/p>\n\n\n\n

Table 1: Summary of the results Relative Standard Deviation (RSD \/ %) of the suppressor comparison using the Hamilton PRP-X100 column (4 \u00d7 50 mm). The flow rate was set to 1\u202fmL\/min with an eluent consisting of 2.2\u202fmM sodium carbonate, 2.8\u202fmM sodium bicarbonate and 0.1\u202fmM ammonium thiocyanate. The column temperature was maintained at 40\u202f\u00b0C throughout the measurements and the injection volume 20 \u00b5L.<\/strong><\/p>\n\n\n\n

Suppressor<\/strong><\/td>Fluoride<\/strong><\/td>Chloride<\/strong><\/td>Nitrite<\/strong><\/td>Bromide<\/strong><\/td>Nitrate<\/strong><\/td>Phosphate<\/strong><\/td>Sulfate<\/strong><\/td><\/tr>
A\/ RSD %<\/td>1.02<\/td>0.37<\/td>4.19<\/td>1.22<\/td>0.99<\/td>0.90<\/td>0.22<\/td><\/tr>
B\/ RSD %<\/td>0.58<\/td>0.34<\/td>5.30<\/td>1.28<\/td>1.64<\/td>0.82<\/td>0.29<\/td><\/tr>
C\/ RSD %<\/td>1.05<\/td>0.52<\/td>3.92<\/td>1.25<\/td>1.00<\/td>2.30<\/td>0.52<\/td><\/tr>
D\/ RSD %<\/td>0.92<\/td>0.80<\/td>3.23<\/td>1.03<\/td>1.77<\/td>1.24<\/td>0.38<\/td><\/tr>
1 \/ RSD %<\/td>1.04<\/td>2.26<\/td>1.93<\/td>3.37<\/td>4.50<\/td>6.07<\/td>3.36<\/td><\/tr>
2 \/ RSD %<\/td>1.56<\/td>1.35<\/td>3.72<\/td>0.69<\/td>3.07<\/td>0.36<\/td>1.08<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

As this column is already used in our final quality control testing, it was chosen as the starting point for the suppressor evaluation to provide a well-established reference point. The data regarding Supp\u00b2 for Nitrite is affected by the carbonate dip behind the Nitrite peak. This will have a varying impact on the Nitrite integration. The integration of Bromide and Nitrate is elevated due to shared baseline integration.<\/p>\n\n\n\n

The data produced from this shared baseline is impacted by the broader peak areas produced by the PRP-X100.  The PRP-X100 is a durable, resilient anion column, and when used with the Suppressor2<\/sup><\/strong> produces reproducible results. However, some of the analytes are not baseline resolved, due to the column, not the Suppressor, thus the % RSD is higher.<\/p>\n\n\n\n

Table 2: Summary of the results Relative Standard Deviation (RSD %) of the suppressor comparison using the memSep300HC (4 \u00d7 250 mm). The flow rate was set to 1\u202fmL\/min with an eluent consisting of 2.0\u202fmM sodium carbonate, and 0.05\u202fmM ammonium thiocyanate. The column temperature was maintained at 40\u202f\u00b0C throughout the measurements and the injection volume 20 \u00b5L.<\/strong><\/p>\n\n\n\n

Suppressor<\/strong><\/td>Fluoride<\/strong><\/td>Chloride<\/strong><\/td>Nitrite<\/strong><\/td>Bromide<\/strong><\/td>Nitrate<\/strong><\/td>Phosphate<\/strong><\/td>Sulfate<\/strong><\/td><\/tr>
A\/ RSD %<\/td>2.83<\/td>0.70<\/td>1.45<\/td>0.38<\/td>0.32<\/td>1.08<\/td>0.24<\/td><\/tr>
B\/ RSD %<\/td>3.24<\/td>0.74<\/td>0.54<\/td>0.81<\/td>0.58<\/td>1.10<\/td>0.19<\/td><\/tr>
C\/ RSD %<\/td>1.58<\/td>0.29<\/td>0.71<\/td>0.26<\/td>0.92<\/td>0.56<\/td>0.14<\/td><\/tr>
D\/ RSD %<\/td>0.92<\/td>0.80<\/td>3.23<\/td>1.03<\/td>1.77<\/td>1.24<\/td>0.38<\/td><\/tr>
1 \/ RSD %<\/td>0.27<\/td>0.81<\/td>2.07<\/td>0.59<\/td>0.52<\/td>1.10<\/td>0.25<\/td><\/tr>
2 \/ RSD %<\/td>0.19<\/td>1.51<\/td>2.45<\/td>1.50<\/td>1.86<\/td>0.55<\/td>0.76<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

The deviation for fluoride is slightly higher and more variable as fluoride elutes immediately after the water dip. This causes slight shifts in the initial peak position, which in turn affects data acquisition accuracy.<\/p>\n\n\n\n

Table 3: Summary of the results Relative Standard Deviation (RSD %) of the suppressor comparison using the Shodex Si504E (4 \u00d7 250 mm). The flow rate was set to 0.7\u202fmL\/min, with an eluent consisting of 3.2\u202fmM sodium carbonate, 1.0\u202fmM sodium bicarbonate and 0.05 mM ammonium thiocyanate. The column temperature was maintained at 40\u202f\u00b0C throughout the measurements and the injection volume 20 \u00b5L.<\/strong><\/p>\n\n\n\n

Suppressor<\/strong><\/td>Fluoride<\/strong><\/td>Chloride<\/strong><\/td>Nitrite<\/strong><\/td>Bromide<\/strong><\/td>Nitrate<\/strong><\/td>Phosphate<\/strong><\/td>Sulfate<\/strong><\/td><\/tr>
A\/ RSD %<\/td>0.32<\/td>0.25<\/td>4.09<\/td>0.45<\/td>0.17<\/td>1.76<\/td>0.37<\/td><\/tr>
B\/ RSD %<\/td>0.71<\/td>0.62<\/td>4.77<\/td>0.92<\/td>0.68<\/td>0.99<\/td>0.45<\/td><\/tr>
C\/ RSD %<\/td>1.63<\/td>0.52<\/td>2.64<\/td>1.00<\/td>0.46<\/td>1.93<\/td>0.24<\/td><\/tr>
D\/ RSD %<\/td>1.04<\/td>0.38<\/td>3.48<\/td>0.37<\/td>0.37<\/td>1.28<\/td>0.72<\/td><\/tr>
1 \/ RSD %<\/td>0.41<\/td>0.33<\/td>0.33<\/td>1.41<\/td>0.36<\/td>1.05<\/td>0.44<\/td><\/tr>
2 \/ RSD %<\/td>0.62<\/td>0.65<\/td>2.71<\/td>1.14<\/td>1.82<\/td>1.70<\/td>1.37<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

The data for Nitrite is affected by the carbonate dip behind the Nitrite peak. This will have varying impact on the Nitrite integration. The data for Nitrite is effected by the carbonate elution though hardly noticed visually, it is a variable that can impact the resolution and ultimate area counts of Nitrite on this column.<\/p>\n\n\n\n

\"\"
Fig. 1: Overlays of Nitrite elution of seven injections are showing effect of carbonate overtime on the Nitrite peak.<\/sup><\/strong><\/figcaption><\/figure>\n\n\n\n

Table 4: Summary of the results Relative Standard Deviation (RSD %) of the suppressor comparison using the memSep2FA (4.6 \u00d7 250 mm). The flow rate was set to 1\u202fmL\/min with an eluent consisting of 3.2\u202fmM sodium carbonate, 1.0 mM and sodium bicarbonate. The column temperature was maintained at 40\u202f\u00b0C throughout the measurements and the injection volume 20 \u00b5L.<\/strong><\/p>\n\n\n\n

Suppressor<\/strong><\/td>Fluoride<\/strong><\/td>Chloride<\/strong><\/td>Nitrite<\/strong><\/td>Bromide<\/strong><\/td>Nitrate<\/strong><\/td>Phosphate<\/strong><\/td>Sulfate<\/strong><\/td><\/tr>
A\/ RSD %<\/td>2.49<\/td>0.63<\/td>4.49<\/td>0.67<\/td>1.49<\/td>0.43<\/td>0.43<\/td><\/tr>
B\/ RSD %<\/td>0.57<\/td>0.45<\/td>8.17<\/td>0.39<\/td>0.87<\/td>1.40<\/td>0.70<\/td><\/tr>
C\/ RSD %<\/td>1.10<\/td>0.88<\/td>8.01<\/td>1.20<\/td>1.07<\/td>1.32<\/td>0.70<\/td><\/tr>
D\/ RSD %<\/td>0.91<\/td>0.56<\/td>4.85<\/td>0.82<\/td>1.01<\/td>0.88<\/td>0.34<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Other manufacturers typically specify a 3% relative standard deviation (RSD) for chloride, based on a 10\u202fppm standard and a 50\u202f\u00b5L injection loop. In our measurements RSD values for chloride and most other analytes remained below this threshold, even when using a 1\u202fppm chloride standard and a 20\u202f\u00b5L injection volume. Only Nitrite showed higher variability likely due to carbonate interference.<\/p>\n\n\n\n

Conclusions<\/strong><\/p>\n\n\n\n

The comprehensive study and the comparison of various chromatography columns demonstrated a clear improvement in performance when using the new suppressor. Instances where the RSD values were higher could be attributed to separation, related factors rather than the suppressor itself.<\/p>\n\n\n\n

While further optimization of parameters such as column choice, eluent composition or flow rate may help reduce variability in those cases, this was not the focus of the present study.<\/strong><\/p>\n\n\n\n

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

Our ion chromatograph is designed with high flexibility allowing it to operate with\u00a0 common brands of chromatography columns without restriction. Recently, we have added a new suppressor to our product portfolio which like its predecessor operates using chemical regeneration. The following results present partially a comparative performance evaluation of various chromatography columns tested with the […]<\/p>\n","protected":false},"author":19,"featured_media":39695,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"wds_primary_category":0,"footnotes":""},"categories":[174],"tags":[191,176,185,179,184,192,182,175,177,193,189,183,181,186,188,180,190,187,178],"class_list":["post-40169","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tech-note-innovation-2","tag-analytical-methods","tag-anion-analysis","tag-bromide-determination","tag-chemical-regeneration","tag-chloride-determination","tag-chromatography-columns","tag-fluoride-determination","tag-ion-chromatography","tag-membrane-suppressor","tag-memsep2fa","tag-memsep300hc","tag-nitrate-determination","tag-nitrite-analysis","tag-phosphate-analysis","tag-prp-x100","tag-rsd-analysis","tag-shodex-si504e","tag-sulfate-analysis","tag-suppressor-comparison"],"rttpg_featured_image_url":{"full":["https:\/\/membrapure.de\/wp-content\/uploads\/2025\/05\/Background_Ionus-1-1.png",644,528,false],"landscape":["https:\/\/membrapure.de\/wp-content\/uploads\/2025\/05\/Background_Ionus-1-1.png",644,528,false],"portraits":["https:\/\/membrapure.de\/wp-content\/uploads\/2025\/05\/Background_Ionus-1-1.png",644,528,false],"thumbnail":["https:\/\/membrapure.de\/wp-content\/uploads\/2025\/05\/Background_Ionus-1-1-150x150.png",150,150,true],"medium":["https:\/\/membrapure.de\/wp-content\/uploads\/2025\/05\/Background_Ionus-1-1-300x246.png",300,246,true],"large":["https:\/\/membrapure.de\/wp-content\/uploads\/2025\/05\/Background_Ionus-1-1.png",644,528,false],"1536x1536":["https:\/\/membrapure.de\/wp-content\/uploads\/2025\/05\/Background_Ionus-1-1.png",644,528,false],"2048x2048":["https:\/\/membrapure.de\/wp-content\/uploads\/2025\/05\/Background_Ionus-1-1.png",644,528,false],"woocommerce_thumbnail":["https:\/\/membrapure.de\/wp-content\/uploads\/2025\/05\/Background_Ionus-1-1-300x300.png",300,300,true],"woocommerce_single":["https:\/\/membrapure.de\/wp-content\/uploads\/2025\/05\/Background_Ionus-1-1.png",600,492,false],"woocommerce_gallery_thumbnail":["https:\/\/membrapure.de\/wp-content\/uploads\/2025\/05\/Background_Ionus-1-1-100x100.png",100,100,true]},"rttpg_author":{"display_name":"Annalena Bittner","author_link":"https:\/\/membrapure.de\/de\/author\/annalena\/"},"rttpg_comment":0,"rttpg_category":"Tech Note Innovation<\/a>","rttpg_excerpt":"Our ion chromatograph is designed with high flexibility allowing it to operate with\u00a0 common brands of chromatography columns without restriction. Recently, we have added a new suppressor to our product portfolio which like its predecessor operates using chemical regeneration. The following results present partially a comparative performance evaluation of various chromatography columns tested with the…","_links":{"self":[{"href":"https:\/\/membrapure.de\/de\/wp-json\/wp\/v2\/posts\/40169","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/membrapure.de\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/membrapure.de\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/membrapure.de\/de\/wp-json\/wp\/v2\/users\/19"}],"replies":[{"embeddable":true,"href":"https:\/\/membrapure.de\/de\/wp-json\/wp\/v2\/comments?post=40169"}],"version-history":[{"count":0,"href":"https:\/\/membrapure.de\/de\/wp-json\/wp\/v2\/posts\/40169\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/membrapure.de\/de\/wp-json\/wp\/v2\/media\/39695"}],"wp:attachment":[{"href":"https:\/\/membrapure.de\/de\/wp-json\/wp\/v2\/media?parent=40169"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/membrapure.de\/de\/wp-json\/wp\/v2\/categories?post=40169"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/membrapure.de\/de\/wp-json\/wp\/v2\/tags?post=40169"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}