This test quantifies L-Glycine, an important amino acid, in raw materials, powders, capsules, and finished products using Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS). The method offers precise and sensitive measurement down to low microgram per gram levels, ensuring product quality and compliance with formulation specifications.

Samples are extracted with an aqueous solvent and filtered prior to analysis. L-Glycine is separated by liquid chromatography and detected using tandem mass spectrometry in multiple reaction monitoring (MRM) mode targeting specific glycine transitions. Quantification is performed using a calibration curve constructed from certified reference standards. Method accuracy and precision are verified through duplicate injections and recovery assessment of spiked samples.

Results are reported in mg/g (raw material) or mg/serving (finished product). Testing confirms label accuracy, ensures consistent potency, and verifies raw material purity.

This test quantifies L-histidine — a semi-essential amino acid that serves as a precursor to histamine and carnosine, and plays important roles in immune regulation, oxygen transport via hemoglobin, and tissue repair — in dietary supplements, protein blends, amino acid formulations, and raw materials using Liquid Chromatography coupled with Tandem Mass Spectrometry (LC-MS/MS). Accurate quantification is important for label claim verification in amino acid and protein supplement products. LC-MS/MS provides the sensitivity and compound-specific selectivity needed to accurately quantify L-histidine in complex amino acid matrices, where its unique imidazole side chain can present challenges for certain chromatographic methods. Results are reported as a percentage or in milligrams per gram or per serving.

A representative sample is accurately weighed and dissolved or hydrolyzed in a suitable aqueous solvent. An isotopically labeled internal standard (e.g., ¹³C- or ²H-labeled L-histidine) is added prior to sample preparation to correct for matrix effects and recovery variability. The extract is filtered and analyzed by reversed-phase or HILIC LC-MS/MS, with detection by electrospray ionization (ESI) in positive ion mode using multiple reaction monitoring (MRM) transitions specific to L-histidine. Quantification is performed against a multi-point external calibration curve prepared from a certified L-histidine reference standard. Quality control samples at multiple concentration levels are run concurrently to confirm method accuracy, precision, and linearity throughout the analytical run.

L-histidine's imidazole side chain confers a unique basic character and chromatographic behavior that can make it challenging to retain and resolve on standard reversed-phase columns under typical amino acid analysis conditions. LC-MS/MS with MRM detection provides the compound-specific selectivity and sensitivity needed to unambiguously quantify L-histidine in complex protein and amino acid matrices regardless of chromatographic challenges, ensuring accurate label claim verification. This level of analytical rigor supports raw material qualification and cGMP compliance under 21 CFR 111.

This test confirms the identity of lion's mane mushroom (Hericium erinaceus) in raw materials, extracts, and dietary supplements using High-Performance Thin-Layer Chromatography (HPTLC). Hericium erinaceus is a culinary and medicinal mushroom native to North America, Europe, and Asia, widely used in dietary supplements for its potential to support cognitive function, nerve growth factor (NGF) stimulation, and immune health. Its characteristic phytochemical profile includes hericenones (from the fruiting body) and erinacines (from the mycelium), along with polysaccharides and other secondary metabolites. HPTLC identity testing generates a characteristic chromatographic fingerprint that is compared against an authenticated H. erinaceus reference standard to confirm species identity and detect potential adulteration, substitution, or misidentification with related Hericium species or inferior fungal materials.

A representative sample is accurately weighed and extracted using an appropriate solvent system (e.g., methanol or ethanol) to capture the characteristic secondary metabolite profile of H. erinaceus, including hericenones and other lipophilic marker compounds. The extract is applied alongside a certified lion's mane reference standard and, where applicable, potential adulterant or related species extracts, onto an HPTLC silica gel plate using an automated sample applicator. The plate is developed in a validated solvent system optimized to resolve the characteristic marker compounds of H. erinaceus. After development, the plate is derivatized with an appropriate reagent (e.g., anisaldehyde-sulfuric acid or vanillin-sulfuric acid) and evaluated under white light and UV light at 254 nm and 366 nm. The resulting fingerprint pattern is compared visually and, where applicable, by densitometric analysis to the authenticated reference standard in accordance with established HPTLC identity testing guidelines.

Lion's mane is subject to adulteration and species substitution, particularly given the existence of closely related Hericium species (e.g., H. coralloides, H. americanum) and the variability in quality between fruiting body and mycelium-based materials. HPTLC fingerprinting provides a holistic, multi-compound chromatographic identity confirmation that distinguishes authentic H. erinaceus from related species and non-fungal adulterants, offering a level of discriminatory power that single-marker potency assays cannot provide. This method aligns with USP botanical identity testing guidelines and supports cGMP compliance under 21 CFR 111, ensuring that only correctly identified raw materials are used in finished products.

This test quantifies L-isoleucine — one of the three branched-chain amino acids (BCAAs), alongside leucine and valine — in dietary supplements, protein blends, amino acid formulations, and raw materials using Liquid Chromatography coupled with Tandem Mass Spectrometry (LC-MS/MS). L-isoleucine plays a critical role in muscle protein synthesis, energy metabolism, and blood glucose regulation, and is a key component of BCAA and sports nutrition products. LC-MS/MS provides the sensitivity and specificity needed to accurately quantify L-isoleucine and distinguish it from its structural isomers, including L-leucine and L-norvaline, in complex amino acid matrices. Results are reported as a percentage or in milligrams per serving to support label claim verification and cGMP compliance.

A representative sample is accurately weighed and dissolved or hydrolyzed in a suitable aqueous solvent. An isotopically labeled internal standard (e.g., ¹³C- or ²H-labeled L-isoleucine) is added prior to sample preparation to correct for matrix effects and recovery variability. The sample is filtered and injected onto a reversed-phase or HILIC LC column for chromatographic separation. Detection is performed by electrospray ionization (ESI) in positive ion mode, with multiple reaction monitoring (MRM) transitions selected to provide highly specific quantification of L-isoleucine. Quantification is performed against a multi-point external calibration curve prepared from a certified L-isoleucine reference standard. Quality control samples at multiple concentration levels are analyzed concurrently to confirm method accuracy, precision, and linearity.

L-isoleucine is structurally identical in molecular weight to L-leucine and shares near-identical chromatographic behavior under many standard HPLC conditions, making accurate differentiation and quantification of individual BCAAs particularly challenging in complex amino acid matrices. LC-MS/MS with MRM detection provides the compound-specific selectivity needed to unambiguously quantify L-isoleucine alongside its structural isomers, ensuring that BCAA ratios and individual amino acid label claims are accurately verified. This level of analytical rigor is essential for sports nutrition products where precise BCAA ratios are a key product differentiator and consumer expectation.

A specific assay for Listeria monocytogenes, a pathogenic species that can cause listeriosis.

Enrichment, selective plating, and confirmation through biochemical or molecular methods. Reported as presence/absence per 25g.

Must be absent in food products due to its risk to pregnant individuals and immunocompromised populations.

This test detects Listeria spp., a group of bacteria that includes species harmful to immunocompromised individuals.

Samples are enriched and plated on selective agar, with further testing to confirm genus. Results are typically qualitative.

Listeria species should be absent in ready-to-eat products to meet regulatory standards.

This test quantifies L-leucine, an essential branched-chain amino acid (BCAA) and the primary trigger of muscle protein synthesis via the mTOR pathway, in dietary supplements, protein powders, and raw materials using Liquid Chromatography with Tandem Mass Spectrometry (LC-MS/MS). L-leucine is one of the most widely used amino acids in sports nutrition and recovery formulations, and accurate quantification is critical for label claim verification and ensuring consistent dosing across batches. Results are reported in mg per serving or mg per gram to support cGMP compliance.

A representative sample is weighed and extracted using an aqueous acidic solvent or protein precipitation with acetonitrile to isolate free L-leucine from the matrix. The clarified extract is injected onto a reversed-phase or HILIC column coupled to a triple quadrupole mass spectrometer operating in positive ionization Multiple Reaction Monitoring (MRM) mode. Specific precursor-to-product ion transitions characteristic of L-leucine are monitored for quantification and identity confirmation. Quantification is performed against a multi-point calibration curve prepared from a certified L-leucine reference standard, with a stable isotope-labeled internal standard used to correct for matrix effects and ensure accurate recovery across sample types.

L-leucine shares near-identical molecular weight and chromatographic behavior with its structural isomers L-isoleucine and L-norleucine, making UV-based HPLC methods insufficient for unambiguous quantification in complex supplement matrices. LC-MS/MS in MRM mode provides the molecular selectivity required to distinguish L-leucine from its isomers and accurately quantify it at the levels present in high-dose amino acid and BCAA formulations, supporting reliable label claim substantiation and batch-to-batch consistency.

This test quantifies L-Lysine, an essential amino acid important for nutritional labeling and quality control, using Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS). It is applicable to various matrices including raw materials, finished products, capsules, and powders. The method provides sensitive detection with quantification limits down to low microgram per gram levels, ensuring accurate measurement in complex formulations.

Samples are prepared by aqueous extraction followed by filtration to remove particulates. The extract is injected into an LC-MS/MS system equipped with a reverse-phase column, using multiple reaction monitoring (MRM) mode to detect L-Lysine transitions. Quantification is performed using a calibration curve constructed from certified L-Lysine reference standards, with an isotopically labeled internal standard to correct for matrix effects and instrument variability. Method accuracy is verified through duplicate injections, quality control samples, and spike recovery experiments.

Results are reported in mg/g (raw materials) or mg/serving (finished products). Testing confirms label claims, ensures raw material purity, and verifies batch-to-batch consistency in production.

This test quantifies L-methionine — an essential sulfur-containing amino acid that serves as the precursor to S-adenosylmethionine (SAMe), cysteine, and glutathione, and plays a central role in methylation reactions, liver detoxification, and antioxidant defense — in dietary supplements, protein blends, amino acid formulations, and raw materials using Liquid Chromatography coupled with Tandem Mass Spectrometry (LC-MS/MS). Accurate quantification is important for label claim verification and for confirming the methionine contribution in complete protein and multi-amino acid formulations. LC-MS/MS provides the sensitivity and compound-specific selectivity needed to accurately quantify L-methionine in complex matrices. Results are reported as a percentage or in milligrams per gram or per serving.

A representative sample is accurately weighed and dissolved or hydrolyzed in a suitable aqueous solvent, with care taken to minimize oxidation of the sulfur-containing side chain during sample preparation. An isotopically labeled internal standard (e.g., ¹³C- or ²H-labeled L-methionine) is added prior to sample preparation to correct for matrix effects and recovery variability. The extract is filtered and analyzed by reversed-phase or HILIC LC-MS/MS, with detection by electrospray ionization (ESI) in positive ion mode using multiple reaction monitoring (MRM) transitions specific to L-methionine. Quantification is performed against a multi-point external calibration curve prepared from a certified L-methionine reference standard. Quality control samples at multiple concentration levels are run concurrently to confirm method accuracy, precision, and linearity throughout the analytical run.

L-methionine is an essential amino acid with a reactive sulfur-containing side chain that is susceptible to oxidation to methionine sulfoxide during processing and storage, potentially reducing bioavailability and potency. LC-MS/MS with MRM detection provides the compound-specific selectivity needed to specifically quantify intact L-methionine and distinguish it from its oxidized form and other sulfur-containing amino acids such as cysteine and homocysteine in complex matrices. This level of analytical rigor supports label claim accuracy, raw material qualification, and cGMP compliance under 21 CFR 111.

This test quantifies L-phenylalanine — an essential aromatic amino acid that serves as a precursor to tyrosine, dopamine, norepinephrine, and epinephrine — in dietary supplements, amino acid blends, protein hydrolysates, and raw materials using High-Performance Liquid Chromatography (HPLC). Accurate quantification is critical for label claim verification, ensuring that the declared amount of this essential amino acid is present in the finished product. This test is also relevant for products bearing phenylalanine content disclosures required for individuals with phenylketonuria (PKU), a metabolic disorder in which phenylalanine cannot be properly metabolized. Results are reported as a percentage or in milligrams per serving.

A representative sample is accurately weighed and hydrolyzed under acidic conditions (e.g., 6N hydrochloric acid at elevated temperature) if present in a protein-bound form, or dissolved directly in a suitable buffer if in free amino acid form. The sample is derivatized using a pre-column or post-column reagent — such as o-phthalaldehyde (OPA), phenylisothiocyanate (PITC), or 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) — to enable UV or fluorescence detection. Separation is performed by reversed-phase HPLC on a C18 column, and quantification is performed against a multi-point external calibration curve prepared from a certified L-phenylalanine reference standard. System suitability and quality control standards are run concurrently to confirm method accuracy and precision.

L-phenylalanine is an essential amino acid that cannot be synthesized by the human body and must be obtained through diet or supplementation, making accurate potency verification important for product efficacy and consumer safety. Critically, phenylalanine is a mandatory disclosure ingredient for individuals with PKU, and inaccurate labeling of phenylalanine content in food and supplement products poses a direct health risk to this population. HPLC with derivatization provides the sensitivity and specificity needed to accurately quantify L-phenylalanine in complex amino acid and protein matrices, supporting both label claim compliance and regulatory disclosure requirements under 21 CFR 101 and 111.

This test quantifies L-Proline, an important amino acid relevant for nutritional and quality assessment, using Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS). It is applicable to various matrices including raw materials, powders, capsules, and finished products. The method provides sensitive detection with a reporting limit of 0.1 mg/kg, ensuring accurate measurement for quality control purposes.

Samples are prepared by extracting 0.5 g of material with 10 mL of 0.1% formic acid in water, followed by centrifugation and filtration. The extract is analyzed using LC-MS/MS with electrospray ionization in positive mode, monitoring L-Proline transitions in multiple reaction monitoring (MRM) mode. Quantification is performed using an external calibration curve constructed from certified L-Proline standards ranging from 0.1 to 100 mg/L. Quality control includes duplicate injections, analysis of spiked samples for recovery assessment, and periodic injection of QC standards to verify instrument performance.

Results are reported in mg/g (raw material) or mg/serving (finished product). Testing confirms label accuracy, verifies raw material purity, and supports consistent manufacturing quality.

This assay quantifies L-theanine, a naturally occurring amino acid found in green tea and commonly used in calming and nootropic supplements. Using HPLC, it verifies L-theanine content in capsules, powders, and beverages to confirm label claims and ensure consistent dosing.

Samples are extracted in aqueous or acidic solution and analyzed by HPLC with UV detection at a compound-specific wavelength. Quantification is performed using certified L-theanine standards, with internal standard correction and duplicate injections to ensure accuracy and reproducibility.

Results are reported in mg per g or per serving. Values are compared to formulation targets and label claims to confirm active content and detect any degradation or underformulation.

This test quantifies L-threonine — an essential amino acid that plays a critical role in protein synthesis, immune globulin production, intestinal mucosal integrity, and collagen formation — in dietary supplements, protein blends, amino acid formulations, and raw materials using Liquid Chromatography coupled with Tandem Mass Spectrometry (LC-MS/MS). Accurate quantification is important for label claim verification in amino acid and protein supplement products, as well as for confirming the threonine contribution in complete protein and BCAA formulations. LC-MS/MS provides the sensitivity and compound-specific selectivity needed to accurately quantify L-threonine in complex amino acid matrices. Results are reported as a percentage or in milligrams per gram or per serving.

A representative sample is accurately weighed and dissolved or hydrolyzed in a suitable aqueous solvent. An isotopically labeled internal standard (e.g., ¹³C- or ²H-labeled L-threonine) is added prior to sample preparation to correct for matrix effects and recovery variability. The extract is filtered and analyzed by reversed-phase or HILIC LC-MS/MS, with detection by electrospray ionization (ESI) in positive ion mode using multiple reaction monitoring (MRM) transitions specific to L-threonine. Quantification is performed against a multi-point external calibration curve prepared from a certified L-threonine reference standard. Quality control samples at multiple concentration levels are run concurrently to confirm method accuracy, precision, and linearity throughout the analytical run.

L-threonine is an essential amino acid that cannot be synthesized by the human body, making accurate potency verification important for confirming that supplement products deliver the declared dose. LC-MS/MS with MRM detection provides the compound-specific selectivity needed to unambiguously quantify L-threonine in complex protein and amino acid matrices, where co-eluting amino acids may interfere with less selective analytical methods. This level of analytical rigor supports label claim accuracy, raw material qualification, and cGMP compliance under 21 CFR 111.

This test quantifies L-Tryptophan, an essential amino acid important for nutritional and quality control purposes, using Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS). It is suitable for analyzing raw materials, finished products, capsules, and powders. The method provides high specificity and sensitivity with detection limits typically in the low nanogram per milliliter range.

Samples are first extracted with a methanol-water solution to release L-Tryptophan, followed by filtration to remove particulates. The extract is injected into an LC-MS/MS system operating in Multiple Reaction Monitoring (MRM) mode, using electrospray ionization in positive mode. Separation is achieved on a reversed-phase C18 column with a gradient mobile phase of water and acetonitrile containing 0.1% formic acid. Quantification is performed using a calibration curve constructed from certified L-Tryptophan standards, with an isotopically labeled internal standard to correct for matrix effects and instrument variability. Method accuracy and precision are verified through duplicate injections, quality control samples, and spike recovery experiments.

Testing confirms label claims, verifies raw material purity, and supports batch-to-batch consistency.

This test quantifies L-Tyrosine, an important amino acid, in raw materials, powders, capsules, and finished products using High-Performance Liquid Chromatography (HPLC). Accurate measurement of L-Tyrosine ensures product quality and compliance with nutritional specifications. The assay has a detection limit of 0.1 mg/g, providing sensitive and precise quantification.

Samples are prepared by aqueous extraction followed by filtration to remove particulates. The extract is injected into an HPLC system equipped with a C18 reversed-phase column and UV detection at 274 nm, specific for L-Tyrosine. Quantification is achieved using an external calibration curve constructed from certified L-Tyrosine reference standards over a defined concentration range. Method precision is confirmed by duplicate injections and quality control samples, while spike recovery tests validate accuracy.

Results are reported in mg/g (raw material) or mg/serving (finished products). Testing confirms label claims, verifies raw material purity, and ensures batch-to-batch consistency in amino acid formulations.

This assay detects and quantifies lupin protein using a validated ELISA (Enzyme-Linked Immunosorbent Assay). It is used to confirm the presence or absence of lupin contamination in raw materials, finished products, and production environments—critical for meeting allergen labeling regulations in regions where lupin is a regulated allergen (e.g., EU, Australia).

Samples are extracted and tested using a sandwich ELISA specific to lupin protein. The method uses antibody-based colorimetric detection and quantifies results using a certified standard curve. Positive and negative controls are included to ensure accuracy.

Results are reported in ppm (mg/kg) of lupin protein. The method typically detects trace levels as low as 1–5 ppm depending on the matrix, making it suitable for allergen-free claim verification or contamination screening.

This assay quantifies lutein, a carotenoid found in marigold extract and leafy greens, commonly used in vision support and antioxidant supplements. Using HPLC, it measures lutein content in raw materials and finished products to confirm potency and support structure-function claims.

Samples are extracted using organic solvents (typically hexane or ethanol-based), then analyzed by HPLC with UV-Vis detection at a compound-specific wavelength (typically ~445 nm). Quantification is performed using certified lutein standards, with internal standard correction and duplicate injections for accuracy.

Results are reported in mg per g or per serving. Values are compared to formulation targets and declared label claims to confirm standardization and detect degradation or adulteration.

This test quantifies L-valine — one of the three branched-chain amino acids (BCAAs), alongside leucine and isoleucine — in dietary supplements, protein blends, amino acid formulations, and raw materials using Liquid Chromatography coupled with Tandem Mass Spectrometry (LC-MS/MS). L-valine plays an important role in muscle tissue repair, nitrogen balance, and energy production during sustained exercise, and is a standard component of BCAA and sports nutrition formulations. LC-MS/MS provides the sensitivity and specificity required to accurately quantify L-valine and distinguish it from co-eluting structural isomers in complex amino acid matrices. Results are reported as a percentage or in milligrams per serving to support label claim verification and cGMP compliance.

A representative sample is accurately weighed and dissolved or hydrolyzed in a suitable aqueous solvent. An isotopically labeled internal standard (e.g., ¹³C- or ²H-labeled L-valine) is added prior to sample preparation to correct for matrix effects and recovery variability. The sample is filtered and injected onto a reversed-phase or HILIC LC column for chromatographic separation. Detection is performed by electrospray ionization (ESI) in positive ion mode, with multiple reaction monitoring (MRM) transitions selected to provide highly specific quantification of L-valine. Quantification is performed against a multi-point external calibration curve prepared from a certified L-valine reference standard. Quality control samples at multiple concentration levels are analyzed concurrently to confirm method accuracy, precision, and linearity throughout the analytical run.

Accurate quantification of individual BCAAs — including L-valine — is essential for verifying the declared BCAA ratio and total amino acid content in sports nutrition products, where precise formulation is a key product claim and consumer expectation. LC-MS/MS with MRM detection provides the compound-specific selectivity needed to unambiguously quantify L-valine alongside leucine and isoleucine in complex protein and amino acid matrices, where standard HPLC methods may not provide sufficient resolution between structural isomers. This level of analytical specificity supports both raw material qualification and finished product release testing under 21 CFR 111 cGMP requirements.

This test quantifies lycopene, a fat-soluble carotenoid pigment found predominantly in tomatoes and tomato-derived ingredients, in dietary supplements, food products, and raw materials using High-Performance Liquid Chromatography with UV/Visible detection (HPLC-UV/Vis). Lycopene is one of the most studied carotenoids for its antioxidant activity and its association with prostate and cardiovascular health. Results are reported in mg per serving or mg per gram to support label claim verification and cGMP compliance.

A representative sample is weighed and subjected to saponification using an ethanolic potassium hydroxide solution to hydrolyze esterified carotenoids, followed by liquid-liquid extraction with an organic solvent such as hexane or ethyl acetate to isolate lycopene. The extract is evaporated under nitrogen, reconstituted in mobile phase, and injected onto a reversed-phase C18 or C30 HPLC column — C30 columns are preferred for improved resolution of lycopene from structurally similar carotenoid isomers. Detection is performed by UV/Vis at approximately 472 nm, corresponding to the characteristic visible absorbance of lycopene. All sample preparation steps are conducted under amber or reduced-light conditions to prevent photodegradation, and quantification is performed against a multi-point external calibration curve prepared from a certified lycopene reference standard.

Lycopene is highly susceptible to oxidative and photodegradation, and its accurate quantification requires careful sample handling combined with a chromatographic method capable of resolving it from cis-isomers and co-present carotenoids such as beta-carotene and phytoene. HPLC with UV/Vis detection at 472 nm provides the sensitivity and selectivity needed for reliable potency measurement across softgel, powder, and oil-based supplement formats, ensuring label claim accuracy and raw material qualification.

This assay detects and quantifies macadamia nut protein using a specific ELISA (Enzyme-Linked Immunosorbent Assay). It verifies the presence or absence of macadamia contamination in raw materials, finished products, or facility environments—helping manufacturers meet allergen labeling regulations and avoid cross-contact issues.

Samples are extracted and analyzed using a macadamia-specific sandwich ELISA. The method uses antibody-based detection with colorimetric readout and compares results to a validated standard curve. Duplicate wells and control samples ensure reliable results.

Results are reported in ppm (mg/kg) of macadamia protein. Detection limits typically range from 1–5 ppm, allowing for sensitive identification of trace contamination to support “nut-free” claims or allergen risk management.

This test confirms the botanical identity of maca root (Lepidium meyenii) in raw materials and finished products using High-Performance Thin-Layer Chromatography (HPTLC). HPTLC generates a characteristic chromatographic fingerprint based on maca's unique glucosinolate and alkaloid marker compounds, which is compared against a certified Lepidium meyenii reference standard to confirm species authenticity and detect substitution or adulteration. Results are reported as confirmed identity or non-conforming.

A representative sample is extracted using methanol or an aqueous-organic solvent system and applied alongside a certified maca root reference standard onto an HPTLC silica gel plate using an automated applicator. The plate is developed in a validated solvent system, dried, and derivatized with an appropriate detection reagent to visualize the characteristic marker bands associated with maca's glucosinolate and macamide profile. The resulting fingerprint is compared visually and by densitometric scanning to the reference standard pattern. Identity is confirmed when the sample fingerprint matches the reference in terms of Rf values, band positions, and color profile, per established HPTLC botanical identity methods.

Maca root is a premium Andean botanical that commands a significant price premium, making it a target for substitution with less expensive root powders or unrelated starch-based fillers. HPTLC identity testing provides a rapid and scientifically defensible confirmation of botanical species, supporting supplier qualification, and label accuracy.

This assay measures magnesium (Mg) using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The method provides highly sensitive and accurate elemental quantification across a wide range of matrices.

Samples are digested and analyzed by ICP-MS under validated conditions. Magnesium is ionized in the plasma and detected by mass spectrometry. Calibration with certified reference standards and internal controls ensures accuracy and reproducibility.

Testing verifies label claims, confirms elemental purity, and supports consistent formulation and regulatory compliance.

This test quantifies total elemental magnesium in blended raw materials and dietary supplements containing multiple magnesium salt forms — specifically magnesium glycinate, magnesium oxide, and magnesium citrate — using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Each magnesium salt form contributes a different theoretical percentage of elemental magnesium (magnesium oxide ~60%, magnesium citrate ~16%, magnesium glycinate ~14%), and accurate measurement of total elemental magnesium is essential for verifying that the combined blend delivers the declared milligrams of elemental magnesium per serving as required under 21 CFR 101 nutritional labeling regulations. ICP-MS provides the sensitivity and multi-element capability needed to precisely quantify magnesium in complex blended matrices. Results are reported in milligrams of elemental magnesium per gram or per serving.

A representative sample is accurately weighed and subjected to complete acid digestion using a validated microwave-assisted or hot block digestion procedure with concentrated nitric acid and, where necessary, hydrochloric acid or hydrogen peroxide, to fully dissolve all magnesium salt forms and convert magnesium to a soluble ionic form. The digested solution is diluted to volume with ultrapure water and analyzed by ICP-MS using an appropriate internal standard (e.g., ⁴⁵Sc or ⁶⁹Ga) to correct for matrix effects and instrument drift. Magnesium is quantified by monitoring the ²⁴Mg isotope against a multi-point external calibration curve prepared from a certified magnesium reference standard traceable to NIST. Certified reference materials and method blanks are analyzed concurrently to confirm digestion efficiency, accuracy, and precision.

ICP-MS is the preferred method for elemental magnesium quantification in complex blended matrices because it provides accurate, precise, and sensitive measurement of total elemental magnesium regardless of the salt form present, without requiring separate assays for each individual magnesium species. This is particularly important for multi-form magnesium blends where the varying solubility and matrix behavior of glycinate, oxide, and citrate salts could compromise the accuracy of less specific methods such as titration or colorimetric assays. Reporting total elemental magnesium ensures direct alignment with label claims and regulatory requirements under 21 CFR 101, and supports raw material qualification and cGMP compliance under 21 CFR 111.

This test quantifies magnesium content in dietary supplements, mineral ingredients, and raw materials using complexometric titration, typically with EDTA (ethylenediaminetetraacetic acid) as the chelating titrant. Magnesium is an essential macromineral involved in over 300 enzymatic reactions, including energy metabolism, muscle contraction, nerve function, and bone health. Titration provides a reliable, cost-effective, and well-established method for determining magnesium content in high-purity mineral salts and supplement formulations. Results are reported as a percentage or in milligrams per gram or per serving to support label claim verification and cGMP compliance.

A representative sample is accurately weighed and dissolved in dilute acid (typically hydrochloric or nitric acid) to ensure complete dissolution of the magnesium salt. The solution is adjusted to an appropriate pH (typically pH 10 using an ammonia buffer) and a metal indicator such as Eriochrome Black T (EBT) or Calmagite is added. The sample is titrated with a standardized EDTA solution until the endpoint color change is observed (from red/wine to blue), indicating complete chelation of the magnesium ions. Magnesium content is calculated from the volume and molarity of EDTA consumed relative to the sample weight. Blank titrations and reference standard checks are performed concurrently to confirm titrant standardization and method accuracy.

Complexometric EDTA titration is a classical, pharmacopoeial-recognized method for the quantification of divalent metal ions including magnesium, and is widely used for the release testing of magnesium-containing raw materials and finished products. The method is particularly well suited for high-purity magnesium salts (e.g., magnesium oxide, magnesium citrate, magnesium glycinate) where magnesium is the primary analyte and matrix interference is minimal. Titration offers a rapid, cost-effective alternative to instrumental methods such as ICP-MS or ICP-OES for routine magnesium quantification, supporting raw material qualification and label claim compliance under 21 CFR 111.