Vitamins
Biologically active substances with positive (as well as negative) biological effects. Their dietary intake can be from foods of both plant and animal origin, additionally also from dietary supplements. To monitor the levels of vitamins, their forms and precursors, modern analytical methods are used, mainly based on the technique of liquid chromatography in conjunction with high-resolution mass spectrometry, or with conventional detectors.
The LC-MS method (KM 27) is used to determine hydrophilic and lipophilic vitamins in foods and food supplements, beverages, mushrooms, blood plasma, milk, etc. The following water- and fat-soluble vitamins are determined: niacin (sum of nicotinic acid and nicotinamide) ; nicotinic acid; nicotinamide; pantothenic acid; folic acid (pteroylmonoglutamic acid); (6S)-5-methyltetrahydrofolic acid (levomefolate); glucosamine; glucosamine salt of (S6)-5-methyltetrahydrofolic acid; vitamin B2 (riboflavin); vitamin B6 (sum of pyridoxine, pyridoxal and pyridoxamine); pyridoxine, pyridoxal; pyridoxamine; vitamin A (retinol), vitamin D2; vitamin D3; vitamin D (sum of vitamin D2 and D3); vitamin E (alpha-tocopherol); vitamin K1 (phylloquinone); vitamin K2 (MK-7). Within the flexible scope of accreditation, other vitamins and their forms can also be added. The determination of ascorbic and dehydroascorbic acid in food, plant materials, beverages and food supplements is carried out by the accredited LC-MS method (KM 25), but the LC-DAD method can also be used. Note: the reception of samples for the determination of group B vitamins is temporarily suspended.
The LC-DAD/FLD (KM 31) method is used for the determination of fat-soluble carotenoids, vitamin A and tocopherols. The method is mainly used for the determination of astaxanthin, β-carotene, canthaxanthin, trans-β-Apo-8′-carotenal, alpha tocopherol and retinol in food, beverages, plant materials, feed, algae, eggs and dietary supplements.
Additives (food additives)
Additives, whether of natural or synthetic origin, are intentionally added to foods for technological purposes such as improving or preserving their durability, appearance, consistency, taste or smell. It is a diverse group of substances, mainly from the categories of organic (synthetic and natural) dyes, sweeteners, preservatives, antioxidants, etc., differing in chemical structure and properties, and their use is regulated by legislation.
To control the levels of additives defined by Regulation (EC) No. 1333/2008 from the group of sweeteners, preservatives and synthetic dyes, the technique of liquid chromatography is used in conjunction with high-resolution mass spectrometry. The determination of additives in food, beverages, food supplements, water, extracts and some other materials (e.g. cosmetic medicinal products) is carried out by an accredited LC-MS method (KM 25). The method is intended for additives from the following groups (according to the function they perform):
- preservatives, especially benzoic acid (E210) and sorbic acid (E200) and their salts;
- synthetic dyes such as azorubin (E122); brilliant blue FCF (E133); black BN (E151); red allura AC (E129); patent blue V (E131); ponceau 4R (E124); tartrazine (E102); green S (E142); yellow SY (E110); etc.
- sweeteners such as acesulfame K (E950); aspartame (E951); cyclamate (E952); neohesperidin DC (E959); neotame E961); saccharin (E954); sucralose (E955).
Using the LC-MS method (KM 25), we also determine other substances added to food, such as caffeine, theobromine, ascorbic acid (E300); dehydroascorbic acid; ascorbyl palmitate (E304) and some flavoring components that are regulated by Regulation (EC) No. 1334/2008.
The LC-MS multi-detection screening method is used to prove the adulteration of food with the addition of unauthorized synthetic substances with a coloring effect, such as fluorescein, but especially the analysis of fat-soluble dyes (e.g. from the Sudan group).
Screening for the presence of synthetic dyes in various technical liquids, possibly in cosmetic and medicinal products is carried out on a non-routine basis according to the specific needs of the client (usually outside the scope of accreditation).