{"id":43351,"date":"2020-10-08T00:00:00","date_gmt":"2020-10-08T00:00:00","guid":{"rendered":"https:\/\/discover.restek.com\/uncategorized\/a-novel-solution-for-vitamin-k1-and-k2-analysis-in-human-plasma-by-lc-msms\/"},"modified":"2026-01-28T15:47:52","modified_gmt":"2026-01-28T15:47:52","slug":"a-novel-solution-for-vitamin-k1-and-k2-analysis-in-human-plasma-by-lc-msms","status":"publish","type":"post","link":"https:\/\/discover.restek.com\/de\/notes-dapplication\/cfan2934\/a-novel-solution-for-vitamin-k1-and-k2-analysis-in-human-plasma-by-lc-msms","title":{"rendered":"A Novel Solution for Vitamin K<sub>1<\/sub> and K<sub>2<\/sub> Analysis in Human Plasma by LC-MS\/MS"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Abstract<\/h2>\n\n\n\n<p>Vitamin K<sub>1<\/sub>&nbsp;and K<sub>2<\/sub>&nbsp;analysis is typically complex and time-consuming because these lipophilic vitamins occur at low levels and are subject to matrix interference, particularly from phospholipids. The new method established here provides fast, accurate, and precise vitamin K analysis in plasma using a simple phospholipid removal procedure and a sensitive, 4-minute LC-MS\/MS analysis on a Raptor Biphenyl column, making it suitable for both research and high-throughput testing.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Introduction<\/h2>\n\n\n\n<p>Vitamin K is a group of fat-soluble vitamins divided into vitamin K<sub>1<\/sub>&nbsp;(one compound, phylloquinone) and K<sub>2<\/sub>&nbsp;(a group of compounds, menaquinones). Among the K<sub>2<\/sub>&nbsp;family, MK4 and MK7 are the most nutritionally recognized. While K<sub>1<\/sub>&nbsp;plays an important role in controlling blood clotting, studies have shown that MK4 and MK7 have distinct biological function in the regulation of bone metabolism and vascular calcification. As interest in their biological action in extra-hepatic tissues is increasing, an accurate and simple measurement of vitamin K status remains a critical issue for both clinical research and diagnostics. Vitamin K<sub>1<\/sub>&nbsp;and K<sub>2<\/sub>&nbsp;analysis is extremely challenging because they are the most lipophilic and least abundant of the fat-soluble vitamins. Common strategies are complex and time-consuming: typical methods use liquid-liquid extraction paired with silica-based SPE to separate polar and nonpolar lipids, followed by post-column derivatization and fluorescence detection. In this study, a simple and fast phospholipid removal sample preparation procedure was developed and used in combination with an LC-MS\/MS analysis using a Raptor Biphenyl column. The method established here provides a novel solution for vitamin K measurement for both research and high-throughput clinical diagnostic labs.<\/p>\n\n\n<div class=\"wp-block-custom-chromatogram-article-top\"><div class=\"chromatogram-article-placeholder\"><div class=\"figure-heading\"><strong>Figure 1:<\/strong>\u00a0Structures of Vitamin K<sub>1<\/sub>\u00a0and K<sub>2<\/sub><\/div><div class='chromatogram-article-inner-full'><div class=\"chromatogram-article-inner\">\n<style>.kb-image43351_096f0f-72 .kb-image-has-overlay:after{opacity:0.3;}<\/style>\n<div class=\"wp-block-kadence-image kb-image43351_096f0f-72\"><figure class=\"aligncenter size-medium_large\"><img loading=\"lazy\" decoding=\"async\" width=\"768\" height=\"555\" src=\"https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-01-768x555.jpg\" alt=\"\" class=\"kb-img wp-image-18958\" title=\"-\" srcset=\"https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-01-768x555.jpg 768w, https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-01-300x217.jpg 300w, https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-01-1024x740.jpg 1024w, https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-01-1536x1109.jpg 1536w, https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-01.jpg 1800w\" sizes=\"auto, (max-width: 768px) 100vw, 768px\" \/><\/figure><\/div>\n\n<\/div><\/div><\/div>\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Experimental<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Calibration Standards and Quality Control Samples<\/h3>\n\n\n\n<p>SeraFlx BIOMATRIX (BioIVT) was fortified with the three vitamin K analytes to prepare calibration standards and QC samples. Seven-point calibration curves established a 0.10-10 ng\/mL linear range. Three QC levels were prepared at 0.25, 0.75, and 8.00 ng\/mL for all three vitamin K analytes. The fortified standards and QC samples were subjected to sample preparation procedure as described further on.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Human Plasma Analysis<\/h3>\n\n\n\n<p>To ensure method applicability across a range of patient populations that vary in endogenous vitamin K levels, multiple human plasma samples (BioIVT) were analyzed. These samples included pooled plasma (from 20 people), plasma from an individual taking vitamin K<sub>2<\/sub>&nbsp;medication, and plasma from an individual of a Japanese descent because the typical Japanese diet is high in MK7-containing foods.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Sample Preparation<\/h3>\n\n\n\n<p>A 500 \u00b5L aliquot of sample was mixed with 5 \u00b5L of internal standard solution (K<sub>1<\/sub>-d7, MK4-d7, and MK7-d7 at 100 ng\/mL in methanol) and 1.5 mL of acetonitrile followed by vortexing for 20 seconds at 3000 rpm. After centrifugation at 4300 rpm for 10 minutes, the supernatant was loaded onto a Biotage ISOLUTE PLD+ 96-well plate (50 mg) and vacuum was applied to collect the eluate. The eluate was then evaporated to dryness at&nbsp;50 \u00b0C under a gentle stream of nitrogen.&nbsp;The dried extract was reconstituted with 100 \u03bcL of&nbsp;15:85 water:methanol&nbsp;and 5 \u03bcL of sample was injected for analysis.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Instrument Conditions<\/h3>\n\n\n\n<p>LC-MS\/MS analysis of vitamin K<sub>1<\/sub>&nbsp;and K<sub>2<\/sub>&nbsp;in human plasma was performed on a Waters Xevo TQ-S mass spectrometer paired with an ACQUITY UPLC system. Instrument conditions were as follows, and analyte transitions are provided in Table I.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\" style=\"border-style:none;border-width:0px\"><tbody><tr><td>Analytical column:<\/td><td colspan=\"2\">Raptor Biphenyl 2.7 \u00b5m, 50 mm x 2.1 mm (cat.#<a href=\"https:\/\/www.restek.com\/p\/9309A52\" target=\"_blank\" rel=\"noopener\">\u00a0<\/a>9309A52)<\/td><\/tr><tr><td>Mobile phase A:<\/td><td colspan=\"2\">Water, 0.1% formic acid, 5 mM ammonium formate<\/td><\/tr><tr><td>Mobile phase B:<\/td><td colspan=\"2\">Methanol, 0.1% formic acid<\/td><\/tr><tr><td>Gradient:<\/td><td>Time (min)&nbsp; &nbsp; &nbsp;<\/td><td>%B<\/td><\/tr><tr><td>&nbsp;<\/td><td>0.00&nbsp;<\/td><td>90<\/td><\/tr><tr><td>&nbsp;<\/td><td>1.00<\/td><td>100<\/td><\/tr><tr><td>&nbsp;<\/td><td>3.00&nbsp;<\/td><td>100<\/td><\/tr><tr><td>&nbsp;<\/td><td>3.01<\/td><td>90<\/td><\/tr><tr><td>&nbsp;<\/td><td>4.00<\/td><td>90<\/td><\/tr><tr><td>Flow rate:<\/td><td>0.4 mL\/min<\/td><td>&nbsp;<\/td><\/tr><tr><td>Injection volume:<\/td><td>5 \u00b5L<\/td><td>&nbsp;<\/td><\/tr><tr><td>Column temp.:<\/td><td>40 \u00b0C<\/td><td>&nbsp;<\/td><\/tr><tr><td>Ion mode:<\/td><td>Positive ESI<\/td><td>&nbsp;<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p><strong>Table I:<\/strong>&nbsp;Analyte Transitions<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th><strong>Analyte<\/strong><\/th><th><strong>Precursor Ion<\/strong><\/th><th><strong>Product Ion Quantifier<\/strong><\/th><th><strong>Product Ion Qualifier<\/strong><\/th><\/tr><\/thead><tbody><tr><td>MK4<\/td><td>445.5<\/td><td>187.2<\/td><td>81.1<\/td><\/tr><tr><td>K<sub>1<\/sub><\/td><td>451.5<\/td><td>187.2<\/td><td>128.2<\/td><\/tr><tr><td>MK7<\/td><td>649.7<\/td><td>187.2<\/td><td>81.1<\/td><\/tr><tr><td>MK4-d7<\/td><td>452.5<\/td><td>194.2<\/td><td>&#8211;<\/td><\/tr><tr><td>K<sub>1<\/sub>-d7<\/td><td>458.5<\/td><td>194.2<\/td><td>&#8211;<\/td><\/tr><tr><td>MK7-d7<\/td><td>656.7<\/td><td>194.2<\/td><td>&#8211;<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Results and Discussion<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Chromatographic Performance<\/h3>\n\n\n\n<p>A fast, 4-minute chromatographic vitamin K<sub>1<\/sub>&nbsp;and vitamin K<sub>2<\/sub>&nbsp;analysis was achieved with injection of reconstituted solution obtained from a simple phospholipid removal procedure. No chromatographic interferences were observed from the analysis of blank plasma samples (Figure 2), indicating the technique provided sufficient removal of matrix components.<\/p>\n\n\n<div class=\"wp-block-custom-chromatogram-article-top\"><div class=\"chromatogram-article-placeholder\"><div class=\"figure-heading\"><strong>Figure 2:<\/strong>\u00a0Analysis of Blank and Fortified SeraFlx BIOMATRIX<\/div><div class='chromatogram-article-inner-full'><div class=\"chromatogram-article-inner\">\n\n<p class=\"has-medium-font-size\"><strong>Blank<\/strong><\/p>\n\n\n<div class=\"wp-block-custom-chromatogram-article\"><div class=\"wp-block-custom-chromatogram-article\"><div class=\"chromatogram-image regular-image\"><img decoding=\"async\" src=\"https:\/\/ez.restek.com\/images\/cgram\/lc_cf0728.png\" alt=\"Vitamin K1 and K2 in Blank Artificial Serum on Raptor Biphenyl by LC-MS\/MS\" title=\"-\"><\/div><p class=\"article-id\" style=\"text-align:center\"> LC_CF0728<\/p><div class=\"chromatogram-pdf-link\"><a href=\"https:\/\/ez.restek.com\/images\/cgram\/lc_cf0728.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"18\" height=\"18\" viewBox=\"0 0 18 18\"><g data-name=\"Group 2996\"><path data-name=\"Rectangle 1246\" d=\"M0 0h18v18H0z\" style=\"fill: none;\"><\/path><\/g><g data-name=\"Group 2997\"><path data-name=\"Path 729\" d=\"M13.412 11.4v2.017H5.345V11.4H4v2.017a1.349 1.349 0 0 0 1.345 1.345h8.068a1.349 1.349 0 0 0 1.345-1.345V11.4zm-.672-2.694-.948-.948-1.741 1.735V4H8.706v5.493L6.965 7.758l-.948.948 3.361 3.361z\" transform=\"translate(-.437 -.414)\" style=\"fill: rgb(13, 123, 196);\"><\/path><\/g><\/svg>Download PDF<\/a><\/div><\/div><\/div>\n\n\n<p class=\"has-medium-font-size\"><strong>0.5 ng\/mL Fortified<\/strong><\/p>\n\n\n<div class=\"wp-block-custom-chromatogram-article\"><div class=\"wp-block-custom-chromatogram-article\"><div class=\"chromatogram-image regular-image\"><img decoding=\"async\" src=\"https:\/\/ez.restek.com\/images\/cgram\/lc_cf0727.png\" alt=\"Vitamin K1 and K2 in Fortified Artificial Serum on Raptor Biphenyl by LC-MS\/MS\" title=\"-\"><\/div><p class=\"article-id\" style=\"text-align:center\"> LC_CF0727<\/p><div class=\"chromatogram-pdf-link\"><a href=\"https:\/\/ez.restek.com\/images\/cgram\/lc_cf0727.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"18\" height=\"18\" viewBox=\"0 0 18 18\"><g data-name=\"Group 2996\"><path data-name=\"Rectangle 1246\" d=\"M0 0h18v18H0z\" style=\"fill: none;\"><\/path><\/g><g data-name=\"Group 2997\"><path data-name=\"Path 729\" d=\"M13.412 11.4v2.017H5.345V11.4H4v2.017a1.349 1.349 0 0 0 1.345 1.345h8.068a1.349 1.349 0 0 0 1.345-1.345V11.4zm-.672-2.694-.948-.948-1.741 1.735V4H8.706v5.493L6.965 7.758l-.948.948 3.361 3.361z\" transform=\"translate(-.437 -.414)\" style=\"fill: rgb(13, 123, 196);\"><\/path><\/g><\/svg>Download PDF<\/a><\/div><\/div><\/div>\n<\/div><\/div><\/div>\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Linearity<\/h3>\n\n\n\n<p>Using 1\/x weighted linear regression, all three analytes showed acceptable linearity with r<sup>2<\/sup>&nbsp;values of 0.995 or greater, and deviations of &lt;15% from the nominal concentrations. The established limit of quantitation was 0.10 ng\/mL. Representative standard curves are shown in Figure 3.<\/p>\n\n\n<div class=\"wp-block-custom-chromatogram-article-top\"><div class=\"chromatogram-article-placeholder\"><div class=\"figure-heading\"><strong>Figure 3:<\/strong>\u00a0Standard Curves<\/div><div class='chromatogram-article-inner-full'><div class=\"chromatogram-article-inner\">\n<style>.kb-image43351_232c3d-17 .kb-image-has-overlay:after{opacity:0.3;}<\/style>\n<div class=\"wp-block-kadence-image kb-image43351_232c3d-17\"><figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"684\" height=\"1024\" src=\"https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-03-684x1024.jpg\" alt=\"\" class=\"kb-img wp-image-18964\" title=\"-\" srcset=\"https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-03-684x1024.jpg 684w, https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-03-200x300.jpg 200w, https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-03-768x1149.jpg 768w, https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-03-1026x1536.jpg 1026w, https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-03-1368x2048.jpg 1368w, https:\/\/discover.restek.com\/wp-content\/uploads\/figure-article-CFAN2934-03-scaled.jpg 1710w\" sizes=\"auto, (max-width: 684px) 100vw, 684px\" \/><\/figure><\/div>\n\n<\/div><\/div><\/div>\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Accuracy and Precision<\/h3>\n\n\n\n<p>Precision and accuracy testing for vitamin K<sub>1<\/sub>&nbsp;and K<sub>2<\/sub>&nbsp;analysis according to the method established here was performed on three different days. The method was demonstrated to be accurate with recovery values falling within 10% of the nominal concentration for all QC levels. The %RSD was 0.207-7.83% and 3.39-5.75% for intraday and interday assessments, respectively, indicating acceptable method precision (Table II).<\/p>\n\n\n\n<p><strong>Table II:<\/strong>&nbsp;Accuracy and Precision of QC Samples for Vitamin K1 and K2 Analysis<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td>&nbsp;<\/td><td colspan=\"3\"><strong>QC-1 (0.250 ng\/mL)<\/strong><\/td><td colspan=\"3\"><strong>QC-2 (0.750 ng\/mL)<\/strong><\/td><td colspan=\"3\"><strong>QC-3 (8.00 ng\/mL)<\/strong><\/td><\/tr><tr><td><strong>Analyte<\/strong><\/td><td><strong>Avg. Conc. (ng\/mL)<\/strong><\/td><td><strong>Avg. Accuracy (%)<\/strong><\/td><td><strong>Precision (%RSD)<\/strong><\/td><td><strong>Avg. Conc. (ng\/mL)<\/strong><\/td><td><strong>Avg. Accuracy (%)<\/strong><\/td><td><strong>Precision (%RSD)<\/strong><\/td><td><strong>Avg. Conc. (ng\/mL)<\/strong><\/td><td><strong>Avg. Accuracy (%)<\/strong><\/td><td><strong>Precision (%RSD)<\/strong><\/td><\/tr><tr><td>K<sub>1<\/sub><\/td><td>0.246<\/td><td>98.2<\/td><td>5.75<\/td><td>0.763<\/td><td>102<\/td><td>3.39<\/td><td>8.23<\/td><td>103<\/td><td>4.36<\/td><\/tr><tr><td>MK4<\/td><td>0.249<\/td><td>100<\/td><td>4.55<\/td><td>0.729<\/td><td>97.2<\/td><td>3.83<\/td><td>8.11<\/td><td>101<\/td><td>5.17<\/td><\/tr><tr><td>MK7<\/td><td>0.245<\/td><td>98.0<\/td><td>3.88<\/td><td>0.715<\/td><td>95.3<\/td><td>4.98<\/td><td>8.23<\/td><td>103<\/td><td>4.76<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Human Plasma Analysis<\/h3>\n\n\n\n<p>Distinct endogenous vitamin K profiles were revealed by analyzing vitamin K<sub>1<\/sub>&nbsp;and vitamin K<sub>2<\/sub>&nbsp;in multiple plasma samples (Figure 4). The analysis of pooled human plasma is a good indication of the average vitamin K level of a collected population. The result showed clear detection of K<sub>1<\/sub>&nbsp;and MK4 in pooled plasma with no detectable MK7, reflecting that the collected population has very low consumption of the MK7-containing food. Conversely, a plasma sample from an individual of Japanese descent showed higher MK7 and no detectable MK4. The plasma sample from an individual taking vitamin K<sub>2<\/sub>&nbsp;medication showed strong K<sub>1<\/sub>, MK4, and MK7 signals. Overall, these results demonstrated that our established method can measure the variation of vitamin K<sub>1<\/sub>&nbsp;and K<sub>2<\/sub>&nbsp;concentrations seen in different populations and is thus applicable for a broad range of clinical samples.<\/p>\n\n\n<div class=\"wp-block-custom-chromatogram-article-top\"><div class=\"chromatogram-article-placeholder\"><div class=\"figure-heading\"><strong>Figure 4:<\/strong>\u00a0Analysis of Endogenous Vitamin K<sub>1<\/sub>\u00a0and K<sub>2<\/sub>\u00a0in Human Plasma<\/div><div class='chromatogram-article-inner-full'><div class=\"chromatogram-article-inner\">\n\n<p class=\"has-medium-font-size\"><strong>Plasma from Patient Taking Vitamin K<sub>2<\/sub>&nbsp;Medication<\/strong><\/p>\n\n\n<div class=\"wp-block-custom-chromatogram-article\"><div class=\"wp-block-custom-chromatogram-article\"><div class=\"chromatogram-image regular-image\"><img decoding=\"async\" src=\"https:\/\/ez.restek.com\/images\/cgram\/lc_cf0730.png\" alt=\"Endogenous Vitamin K1 and K2 in Caucasian Female Plasma (Patient Taking Vitamin K2 Medication) on Raptor Biphenyl\" title=\"-\"><\/div><p class=\"article-id\" style=\"text-align:center\"> LC_CF0730<\/p><div class=\"chromatogram-pdf-link\"><a href=\"https:\/\/ez.restek.com\/images\/cgram\/lc_cf0730.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"18\" height=\"18\" viewBox=\"0 0 18 18\"><g data-name=\"Group 2996\"><path data-name=\"Rectangle 1246\" d=\"M0 0h18v18H0z\" style=\"fill: none;\"><\/path><\/g><g data-name=\"Group 2997\"><path data-name=\"Path 729\" d=\"M13.412 11.4v2.017H5.345V11.4H4v2.017a1.349 1.349 0 0 0 1.345 1.345h8.068a1.349 1.349 0 0 0 1.345-1.345V11.4zm-.672-2.694-.948-.948-1.741 1.735V4H8.706v5.493L6.965 7.758l-.948.948 3.361 3.361z\" transform=\"translate(-.437 -.414)\" style=\"fill: rgb(13, 123, 196);\"><\/path><\/g><\/svg>Download PDF<\/a><\/div><\/div><\/div>\n\n\n<p class=\"has-medium-font-size\"><strong>Pooled Human Plasma Sample<\/strong><\/p>\n\n\n<div class=\"wp-block-custom-chromatogram-article\"><div class=\"wp-block-custom-chromatogram-article\"><div class=\"chromatogram-image regular-image\"><img decoding=\"async\" src=\"https:\/\/ez.restek.com\/images\/cgram\/lc_cf0729.png\" alt=\"Endogenous Vitamin K1 and K2 in Pooled Human Plasma on Raptor Biphenyl\" title=\"-\"><\/div><p class=\"article-id\" style=\"text-align:center\"> LC_CF0729<\/p><div class=\"chromatogram-pdf-link\"><a href=\"https:\/\/ez.restek.com\/images\/cgram\/lc_cf0729.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"18\" height=\"18\" viewBox=\"0 0 18 18\"><g data-name=\"Group 2996\"><path data-name=\"Rectangle 1246\" d=\"M0 0h18v18H0z\" style=\"fill: none;\"><\/path><\/g><g data-name=\"Group 2997\"><path data-name=\"Path 729\" d=\"M13.412 11.4v2.017H5.345V11.4H4v2.017a1.349 1.349 0 0 0 1.345 1.345h8.068a1.349 1.349 0 0 0 1.345-1.345V11.4zm-.672-2.694-.948-.948-1.741 1.735V4H8.706v5.493L6.965 7.758l-.948.948 3.361 3.361z\" transform=\"translate(-.437 -.414)\" style=\"fill: rgb(13, 123, 196);\"><\/path><\/g><\/svg>Download PDF<\/a><\/div><\/div><\/div>\n\n\n<p class=\"has-medium-font-size\"><strong>Plasma from Individual of Japanese Descent<\/strong><\/p>\n\n\n<div class=\"wp-block-custom-chromatogram-article\"><div class=\"wp-block-custom-chromatogram-article\"><div class=\"chromatogram-image regular-image\"><img decoding=\"async\" src=\"https:\/\/ez.restek.com\/images\/cgram\/lc_cf0731.png\" alt=\"Endogenous Vitamin K1 and K2 in Japanese Descent Plasma on Raptor Biphenyl\" title=\"-\"><\/div><p class=\"article-id\" style=\"text-align:center\"> LC_CF0731<\/p><div class=\"chromatogram-pdf-link\"><a href=\"https:\/\/ez.restek.com\/images\/cgram\/lc_cf0731.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"18\" height=\"18\" viewBox=\"0 0 18 18\"><g data-name=\"Group 2996\"><path data-name=\"Rectangle 1246\" d=\"M0 0h18v18H0z\" style=\"fill: none;\"><\/path><\/g><g data-name=\"Group 2997\"><path data-name=\"Path 729\" d=\"M13.412 11.4v2.017H5.345V11.4H4v2.017a1.349 1.349 0 0 0 1.345 1.345h8.068a1.349 1.349 0 0 0 1.345-1.345V11.4zm-.672-2.694-.948-.948-1.741 1.735V4H8.706v5.493L6.965 7.758l-.948.948 3.361 3.361z\" transform=\"translate(-.437 -.414)\" style=\"fill: rgb(13, 123, 196);\"><\/path><\/g><\/svg>Download PDF<\/a><\/div><\/div><\/div>\n<\/div><\/div><\/div>\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Conclusion<\/h2>\n\n\n\n<p>A method was developed for fast, accurate, and precise analysis of vitamin K<sub>1<\/sub>&nbsp;and K<sub>2<\/sub>&nbsp;(MK4 and MK7) in plasma. With quick and easy phospholipid removal sample preparation, 4 minutes of chromatographic analysis using a Raptor Biphenyl column, and sensitive MS\/MS detection, the established method provides a reliable and high-throughput assay for clinical research and assessment of vitamin K<sub>1<\/sub>&nbsp;and K<sub>2<\/sub>.<\/p>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n        <div class=\"cpb\">\n            <h3 class=\"cpb-heading\">Products Mentioned<\/h3>\n            <hr class=\"cpb-heading-underline\" \/>\n            <div class=\"cpb-list\">\n                                    <div class=\"cpb-item\">\n                        <div class=\"cpb-col cpb-col--left\">\n                            <a class=\"cpb-catalog\" target=\"_blank\" rel=\"noopener noreferrer\" href=\"https:\/\/de.restek.com\/p\/9309A52\">                                Catalog No. 9309A52                            <\/a>                        <\/div>\n                        <div class=\"cpb-col cpb-col--middle\">\n                            <div class=\"cpb-title\">Raptor Biphenyl, 2.7 \u00b5m, 50&#215;2.1 mm HPLC-S\u00e4ule<\/div>\n                        <\/div>\n                        <div class=\"cpb-col cpb-col--right\">\n                                                            <a class=\"cpb-view-btn\" target=\"_blank\" rel=\"noopener noreferrer\" href=\"https:\/\/de.restek.com\/p\/9309A52\">Produkt anzeigen<\/a>\n                                                    <\/div>\n                    <\/div>\n                            <\/div>\n        <\/div>\n        \n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Vitamin K1 and K2 analysis is typically complex and time-consuming because these lipophilic vitamins occur at low levels and are subject to matrix interference, particularly from phospholipids. The new method established here provides fast, accurate, and precise vitamin K levels in plasma using a simple phospholipid removal procedure and a sensitive 4-minute LC-MS\/MS analysis on a Raptor Biphenyl column, making it suitable for high-throughput testing.<\/p>\n","protected":false},"author":46,"featured_media":6361,"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":[782],"tags":[],"industries-application":[2200,2201,2202],"post-badge":[],"resource-type":[],"product-library":[2463,2445,2447],"resource-technique":[2318,2362],"hf_cat_post":[651],"ppma_author":[578,586],"class_list":["post-43351","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-notes-dapplication","industries-application-industrie-clinique","industries-application-diagnostics-cliniques","industries-application-recherche-clinique","product-library-colonnes-lc","product-library-produits-pour-la-chromatographie-en-phase-liquide","product-library-produits-pour-la-preparation-dechantillons","resource-technique-chromatographie-en-phase-liquide","resource-technique-ms-ms-fr"],"acf":[],"taxonomy_info":{"category":[{"value":782,"label":"Notes 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