This assay quantifies total inositol content—including the most bioactive isomer, myo-inositol—using LC-MS/MS. It is commonly used in supplements for hormonal health, fertility, and neurological support, and helps confirm potency in single-ingredient and blended formulations.

Samples are extracted in aqueous solution and analyzed by LC-MS/MS using compound-specific mass transitions. Quantification is performed with certified inositol standards, internal standard correction, and duplicate injections to ensure accurate, reproducible results.

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

This assay quantifies iodine content in food samples, which is crucial for nutritional labeling and ensuring adequate intake for thyroid health. The method converts iodine into a measurable form and uses ICPMS for sensitive detection across various food matrices.

Food samples are acid-digested to release iodine, which is sometimes chemically reduced to stabilize the analyte. The prepared solution is introduced into an ICPMS system, where iodine is detected based on its atomic mass. Calibration with iodine standards and internal quality controls ensure the measurement’s accuracy.

Results are provided in ppb. These values allow manufacturers to verify that iodine levels meet nutritional targets and formulation requirements. Consistency across batches indicates stable fortification practices.

This test confirms the identity of Irish sea moss (Chondrus crispus Stackhouse) in raw materials, dried thallus powders, extracts, and dietary supplements using High-Performance Thin-Layer Chromatography (HPTLC). Chondrus crispus, commonly known as Irish moss or carrageen moss, is a red macroalgae (Rhodophyta) native to the rocky Atlantic coastlines of Europe and North America, widely used in dietary supplements for its rich content of carrageenan-type sulfated polysaccharides, iodine, trace minerals, and bioactive pigments including phycoerythrin and carotenoids. HPTLC identity testing generates a characteristic chromatographic fingerprint that is compared against an authenticated C. crispus reference standard to confirm species identity and detect potential adulteration or substitution with other red algae species — particularly Eucheuma spp. and Kappaphycus spp., which are commonly sold as "sea moss" but are botanically and chemically distinct from authentic Chondrus crispus.

A representative sample is accurately weighed and extracted using an appropriate solvent system (e.g., methanol or aqueous ethanol) to capture the characteristic secondary metabolite and pigment profile of C. crispus, including phycoerythrin-derived chromophores, carotenoids, and phenolic compounds. The extract is applied alongside a certified C. crispus reference standard and, where applicable, potential adulterant extracts (e.g., Eucheuma cottonii, Kappaphycus alvarezii), 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 C. crispus. After development, the plate is evaluated under white light and UV light at 254 nm and 366 nm, and may be further derivatized with an appropriate reagent for enhanced visualization of phenolic and pigment constituents. 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.

The market for Irish sea moss supplements has grown rapidly, accompanied by widespread mislabeling and substitution of authentic Chondrus crispus with tropical red algae species — primarily Eucheuma and Kappaphycus species — that are botanically unrelated and differ significantly in their phytochemical composition, mineral content, and carrageenan type. HPTLC fingerprinting provides a holistic, multi-compound chromatographic identity confirmation that distinguishes authentic C. crispus from these common substitutes based on differences in their secondary metabolite and pigment profiles, enabling detection of adulteration that would not be apparent from visual inspection or mineral content testing alone. 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 assay measures iron (Fe) using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The method provides highly sensitive and accurate elemental quantification across diverse matrices.

Samples are digested and analyzed by ICP-MS under validated conditions. Iron 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 panel measures total isothiocyanates using a cyclocondensation reaction followed by HPLC-UV detection. It is commonly used to assess bioactive compounds like sulforaphane in broccoli, kale, and other Brassica-based ingredients.

Samples are reacted with 1,2-benzenedithiol to form a measurable chromophore specific to isothiocyanate groups. The resulting derivative is separated and quantified using HPLC with UV detection. Certified standards and internal calibration curves are used, with duplicate runs to ensure precision.

Results are reported in µmol/g or mg per g. Values are compared to label claims or known reference ranges for Brassica extracts to confirm potency and ingredient quality.

This assay quantifies lactase enzyme activity based on Acid Lactase Units (ALU), following the Food Chemicals Codex (FCC) method. It measures the ability of the lactase enzyme to hydrolyze lactose under acidic conditions, ensuring that products marketed for dairy digestion contain effective enzyme levels.

Samples are incubated with a lactose substrate at an acidic pH. The enzymatic reaction is monitored by measuring the amount of glucose released, which correlates with lactase activity. The method follows the FCC monograph for lactase (ALU definition). Duplicate runs and standard curves using reference enzyme preparations ensure precision and reproducibility.

Results are reported in ALU/g (Acid Lactase Units per gram). Values are assessed against label claims and formulation targets to confirm potency, detect degradation, and ensure consistency across production batches.

This assay quantifies total viable lactic acid bacteria (LAB) in supplements, functional foods, and fermented products. It is commonly used to verify probiotic content, assess fermentation performance, or monitor microbial composition in gut health formulations.

Samples are diluted and plated on selective media such as MRS agar, then incubated under anaerobic or microaerophilic conditions at controlled temperatures. Colonies characteristic of LAB are enumerated after incubation. Testing follows ISO or USP microbiological methods.

Results are reported in CFU/g or CFU/mL. Values are compared to formulation targets or probiotic label claims to confirm viability and consistency across production batches.

This assay measures lactoferrin concentration using an Enzyme-Linked Immunosorbent Assay (ELISA). The method provides high specificity and sensitivity for lactoferrin quantification across dairy-based and formulated supplement products.

Samples are diluted and incubated in microplate wells coated with lactoferrin-specific antibodies. Bound antigen is detected through enzyme-linked secondary antibodies, producing a colorimetric signal proportional to concentration. Quantification is performed against a standard curve generated from known lactoferrin concentrations.

Results are reported in µg/mL (liquids) or mg/g (solids). Testing verifies label claims, confirms ingredient purity, and supports consistency in milk-derived and nutritional formulations.

This assay quantifies lactoperoxidase (LPO), a naturally occurring antimicrobial enzyme found in bovine colostrum and dairy-based ingredients. Using a validated colorimetric method, it measures LPO activity to confirm bioactive content and support immune-related and oral health claims.

Samples are extracted in aqueous buffer, and enzyme activity is measured by monitoring the oxidation of a chromogenic substrate (e.g., ABTS or TMB) in the presence of hydrogen peroxide and thiocyanate. Absorbance is read spectrophotometrically and compared to an LPO activity standard curve.

Results are typically reported in units of activity per gram (U/g). Values are compared to specification targets and used to confirm ingredient identity, potency, and consistency in LPO-containing products.

This assay quantifies lactose, the disaccharide sugar found in milk and dairy-derived ingredients. Using LC-MS/MS, it measures lactose content in raw materials and finished products to verify nutrition label accuracy, confirm lactose levels in dairy formulations, and support “lactose-free” or “low-lactose” claims.

Samples are extracted in aqueous solution, then analyzed by LC-MS/MS using compound-specific mass transitions. Quantification is performed using certified lactose standards, with internal standard correction and duplicate injections to ensure sensitivity, reproducibility, and accuracy.

Results are reported in g per 100 g, g per 100 mL, or per serving. Values are compared with label claims and formulation targets to confirm compliance, detect undeclared lactose, and ensure consumer safety for sensitive populations.

This assay enumerates viable Bacillus coagulans spores in probiotic raw materials and finished products following Method J.4.0002. Results confirm probiotic strength and validate label claims for CFU content.

Samples are prepared, serially diluted, and plated onto selective agar media under specified growth conditions. Colony-forming units (CFUs) are counted after incubation. Method J.4.0002 defines standardized conditions for recovery, ensuring reliable and reproducible results.

Results are reported in CFU/g (raw materials) or CFU/serving (finished products). Testing confirms probiotic viability, verifies stability over shelf life, and ensures compliance with label claims.

This assay quantifies L-arginine, a conditionally essential amino acid involved in nitric oxide synthesis and cardiovascular support. Using LC-MS/MS, it verifies L-arginine content in dietary supplements, functional beverages, and sports nutrition products to confirm label claims and ensure potency.

Samples are extracted in aqueous solution and analyzed by LC-MS/MS using compound-specific mass transitions. Quantification is performed with certified L-arginine standards, applying internal standard correction and duplicate injections for precision and reproducibility.

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

This assay measures L-Arginine Alpha-Ketoglutarate (AAKG), a salt formed from L-arginine and alpha-ketoglutaric acid, using Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS). The method provides high specificity and sensitivity for both components in complex pre-workout and amino acid formulations.

Samples are extracted and analyzed under validated LC-MS/MS chromatographic conditions. AAKG is quantified by detecting the arginine and α-ketoglutarate moieties in multiple reaction monitoring (MRM) mode and calculating total AAKG content against certified reference standards. Internal calibration and quality controls ensure accurate and reproducible results.

Testing verifies label claims, supports formulation consistency, and ensures potency in nitric oxide–boosting and performance-focused products.

This assay measures L-Carnitine L-Tartrate (LCLT), a stabilized and highly bioavailable form of L-carnitine, using Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS). The method provides highly selective and sensitive quantification across raw materials and finished products.

Samples are extracted and analyzed under validated LC-MS/MS chromatographic conditions. L-carnitine is detected via multiple reaction monitoring (MRM) and quantified against certified reference standards. Internal calibration and quality control checks ensure accurate and reproducible results.

Testing confirms label claims, verifies raw material purity, and supports consistency across carnitine-based performance formulations.

This assay quantifies L-citrulline, a conditionally essential amino acid commonly used in pre-workouts and cardiovascular supplements for its role in nitric oxide production. Using HPLC, it verifies the potency of citrulline in finished products and detects degradation or substitution over time.

Samples are extracted in aqueous solution and filtered before analysis. The extract is analyzed by HPLC with detection at a compound-specific wavelength. Quantification is performed using certified L-citrulline standards, with internal standard correction and duplicate runs to ensure accuracy.

Results are reported in mg per g or per serving. Values are compared with label claims and formulation targets. Testing confirms the active dose and verifies product stability throughout shelf life.

This assay measures L-Citrulline Malate using Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS). The method provides highly selective and sensitive quantification of the citrulline component while accounting for its malate salt form in complex sports-nutrition formulations.

Samples are extracted and analyzed under validated LC-MS/MS chromatographic conditions. L-Citrulline is detected in multiple reaction monitoring (MRM) mode and quantified against certified reference standards. Internal calibration and QC checks ensure accuracy, precision, and reproducibility across matrices.

Testing verifies label claims, ensures purity, and confirms consistent potency in citrulline-based performance supplements.

This assay quantifies lead in food samples. It is designed to deliver precise measurements of these contaminants, which are monitored due to their potential toxicity. The robust method employs advanced instrumentation to detect trace levels in complex matrices.

Food samples undergo acid digestion to break down the matrix and release bound metals. The resulting solution is analyzed by an instrument (commonly ICP-MS) that separates and quantifies the metals based on their mass. Calibration with certified reference materials and inclusion of quality control samples ensure accuracy before final reporting.

Results are delivered as concentration values (ppb). Lower values are preferred, and any significant increase may prompt further investigation. The data allow manufacturers to assess overall product safety and track contaminant trends across batches.

This test quantifies L-ergothioneine, a naturally occurring thiohistidine betaine amino acid found at high concentrations in mushrooms and certain other fungi, in dietary supplements and raw materials using High-Performance Liquid Chromatography with UV detection (HPLC-UV). L-ergothioneine has attracted significant research interest for its potent antioxidant properties, cellular protective effects, and its designation by some researchers as a potential longevity vitamin. 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 extracted using an aqueous acidic solvent or methanol-water solvent system with sonication to ensure complete solubilization of L-ergothioneine from the matrix. The extract is filtered, diluted to volume, and injected onto a reversed-phase C18 HPLC column. Detection is performed by UV at approximately 254 nm, utilizing the characteristic UV absorbance of the thiohistidine chromophore. Quantification is performed against a multi-point external calibration curve prepared from a certified L-ergothioneine reference standard, with system suitability and QC samples run concurrently to confirm method accuracy and reproducibility.

L-ergothioneine is an emerging premium ingredient in the supplement market, and accurate quantification is essential for verifying the potency of mushroom-derived extracts and standardized ergothioneine ingredients. HPLC-UV at 254 nm provides adequate selectivity for ergothioneine in most supplement matrices; however, for complex or low-concentration samples, LC-MS/MS may be considered as a confirmatory approach to resolve any co-eluting matrix interferences and ensure label claim accuracy.

This assay quantifies L-glutamine, a conditionally essential amino acid critical for recovery and intestinal barrier support. Using LC-MS/MS, it measures glutamine content in raw materials and finished products to verify potency, ensure label accuracy, and confirm consistency across batches.

Samples are extracted in aqueous solution and analyzed by LC-MS/MS with compound-specific mass transitions. Quantification is performed using certified L-glutamine standards, with internal standard correction and duplicate injections to ensure reproducibility and sensitivity.

Results are reported in mg per g or per serving. Values are compared to label claims and formulation targets to confirm potency, detect degradation, or identify underformulation.

This test measures the concentration of L-glutathione, a key antioxidant, in raw materials, capsules, powders, and finished products to ensure potency, purity, and label compliance. Using high-performance liquid chromatography (HPLC), the method accurately quantifies L-glutathione at low detection limits, supporting quality control in antioxidant and cellular support formulations.

Samples are prepared by extraction with an appropriate solvent to release L-glutathione from the matrix. The extract is then analyzed using HPLC equipped with UV or diode-array detection to separate L-glutathione from other thiol-containing compounds. Quantification is achieved by comparing sample peak areas to a calibration curve constructed from certified L-glutathione reference standards. Method accuracy and precision are confirmed through replicate injections, quality control samples, and spike recovery assessments.

Testing verifies label claims, confirms ingredient purity, and ensures batch-to-batch consistency in glutathione-containing products.

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.