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Jensen MB, Rød KE, Švarc PL, Oveland E, Jakobsen J. Vitamin K (phylloquinone and menaquinones) in foods – Cost-effective quantification by LC-ESI-MS/MS. Food Chem 2022; 385:132672. [DOI: 10.1016/j.foodchem.2022.132672] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 11/04/2022]
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Ložnjak Švarc P, Jensen MB, Langwagen M, Poulsen A, Trolle E, Jakobsen J. Nutrient content in plant-based protein products intended for food composition databases. J Food Compost Anal 2022. [DOI: 10.1016/j.jfca.2021.104332] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Ložnjak Švarc P, Barnkob LL, Jakobsen J. Quantification of vitamin D 3 and 25-hydroxyvitamin D 3 in food - The impact of eluent additives and labelled internal standards on matrix effects in LC-MS/MS analysis. Food Chem 2021; 357:129588. [PMID: 33864998 DOI: 10.1016/j.foodchem.2021.129588] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 02/28/2021] [Accepted: 03/06/2021] [Indexed: 11/15/2022]
Abstract
Deuterated vitamin D standards are used commonly as internal standards in LC-MS/MS analysis of vitamin D3 and 25-hydroxyvitamin D3 in food. However, the use of various eluent additives, such as methylamine, formic acid and ammonium formate, also contributes to matrix effects and the performance of analysis by affecting accuracy and robustness. For the first time, continuous post-column infusion experiments of isotopically labelled vitamin D3-[d6] were performed to evaluate ion-suppression in a wide variety of food (salmon, cheese, pork fat, pork meat, and egg yolk). Furthermore, results collected using five analytical methods, employing DAD/UV and MS/MS-detectors, were evaluated with in-house and standardised reference materials. The matrix effect was significant when analysing vitamin D3 in most food matrices using the deuterium labelled internal standard. Even though the use of the 13C5-labelled internal standard reduced matrix effects, a standardised method is needed to agree on the true value of vitamin D in food.
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Affiliation(s)
- Petra Ložnjak Švarc
- National Food Institute, Technical University of Denmark, Research Group for Bioactives - Analysis and Application, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Line Lundbæk Barnkob
- National Food Institute, Technical University of Denmark, Research Group for Bioactives - Analysis and Application, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Jette Jakobsen
- National Food Institute, Technical University of Denmark, Research Group for Bioactives - Analysis and Application, Kemitorvet, 2800 Kgs. Lyngby, Denmark.
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Ložnjak Švarc P, Oveland E, Strandler HS, Kariluoto S, Campos-Giménez E, Ivarsen E, Malaviole I, Motta C, Rychlik M, Striegel L, Jakobsen J. Collaborative study: Quantification of total folate in food using an efficient single-enzyme extraction combined with LC-MS/MS. Food Chem 2020; 333:127447. [PMID: 32688304 DOI: 10.1016/j.foodchem.2020.127447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/24/2020] [Accepted: 06/27/2020] [Indexed: 12/16/2022]
Abstract
Quantification of the specific folate vitamers to estimate total folate in foods is not standardized. A collaborative study, including eight European laboratories, was conducted in order to determine the repeatability and reproducibility of the method for folate quantification in foods using the plant-origin γ-glutamyl hydrolase as part of the extraction procedure. The seven food samples analyzed represent the food groups; fruits, vegetables, dairy products, legumes, offal, fish, and fortified infant formula. The homogenization step was included, and six folate vitamers were analyzed using LC-MS/MS. Total folate content, expressed as folic acid equivalent, was 17-490 μg/100 g in all samples. Horwitz ratio values were within the acceptable range (0.60-1.94), except for fish. The results for fortified infant formula, a certified reference material (NIST 1869), confirmed the trueness of the method. The collaborative study is part of a standardization project within the Nordic Committee on Food Analysis (NMKL).
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Affiliation(s)
- Petra Ložnjak Švarc
- National Food Institute, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark.
| | - Eystein Oveland
- Institute of Marine Research, P. O. Box 1870, Nordnes, N-5817 Bergen, Norway.
| | | | - Susanna Kariluoto
- University of Helsinki, Department of Food and Nutrition, Agnes Sjöbergin katu 2, FI-00790 Helsinki, Finland.
| | - Esther Campos-Giménez
- Nestle Research, Route du Jorat 57, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland.
| | - Elise Ivarsen
- Eurofins Vitamin Testing, Ladelundvej 85, 6600 Vejen, Denmark.
| | | | - Carla Motta
- National Health Institute, Dr. Ricardo Jorge, Av. Padre Cruz, 1649-016 Lisbon, Portugal.
| | - Michael Rychlik
- Chair of Analytical Food Chemistry, Technical University of Munich, Max-von-Imhof Forum 2, DE-85354 Freising, Germany; Centre for Nutrition and Food Sciences, University of Queensland, St Lucia QLD 4069, Australia.
| | - Lisa Striegel
- Chair of Analytical Food Chemistry, Technical University of Munich, Max-von-Imhof Forum 2, DE-85354 Freising, Germany.
| | - Jette Jakobsen
- National Food Institute, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark.
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Jensen MB, Ložnjak Švarc P, Jakobsen J. Vitamin K (phylloquinone and menaquinones) in foods - Optimisation of extraction, clean-up and LC-ESI-MS/MS method for quantification. Food Chem 2020; 345:128835. [PMID: 33321348 DOI: 10.1016/j.foodchem.2020.128835] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 10/22/2022]
Abstract
Growing evidence of vitamin K's importance in human health beyond blood coagulation and bone health necessitates its further research. A method involving extraction, lipase treatment, clean-up, and detection and quantification by LC-ESI-MS/MS of phylloquinone (PK), menaquinone-4 (MK-4), menaquinone-7 (MK-7) and menaquinone-9 (MK-9) was developed, and single-laboratory validated. The matrices included in the validation were hazelnut, cheese, broccoli, and pork. The LC-method runtime was 9 min. The LOQ for PK, MK-4 and MK-7 was 0.5 µg/100 g food, while for MK-9 it was 2.5 µg/100 g food. The intra- and inter-day precision was <15% for endogenous and spiked levels, except for low content at 4 times the LOQ. Trueness was assessed to be in the range 94-125% for spiking at levels approximately 4 and 10 times LOQ. It is further shown that deuterium labelled MK-7 can be used as an internal standard for MK-9.
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Affiliation(s)
- Marie Bagge Jensen
- Research Group for Bioactives - Analysis and Application, National Food Institute, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark.
| | - Petra Ložnjak Švarc
- Research Group for Bioactives - Analysis and Application, National Food Institute, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark.
| | - Jette Jakobsen
- Research Group for Bioactives - Analysis and Application, National Food Institute, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark.
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