Using Liquid Chromatography-Isotope Ratio Mass Spectrometry for Detection of Economically Motivated Adulteration of Maple Syrup.

Background: Maple syrup is a sought-after commodity, and used as a condiment and a sweetener. Also, it is an active target of economically motivated adulteration (EMA), similar to other foods such as lemon juice and honey.

Objective: This study is aimed to detect low cost sugar adulteration in maple syrup via an internal standard method using malic acid through solid-phase extraction (SPE) and LC with isotope ratio mass spectrometric detection (LC-IRMS).

Using stable carbon isotope ratio analysis to detect adulteration in red yeast rice dietary supplements.

Red yeast rice (RYR) is marketed as a dietary supplement because it contains natural 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), including monacolin K. However, there is concern that some RYR supplements may be adulterated with the pharmaceutical drug lovastatin to enhance health claims. We have developed an optimized method to isolate monacolin K/lovastatin from complex RYR dietary supplement matrices to then test for adulteration in RYR supplements using stable carbon isotope (δC) analysis.

Elemental Analysis of Tetrahydrocannabinol and Nicotine E-Liquids Related to EVALI.

During the e-cigarette, or vaping, product use-associated lung injury (EVALI) investigation, the U.S. FDA's Forensic Chemistry Center (FCC) received numerous sample submissions from various states and other sources.

Economically Motivated Adulteration of Lemon Juice: Cavity Ring Down Spectroscopy in Comparison with Isotope Ratio Mass Spectrometry: Round-Robin Study.

Economically motivated adulteration (EMA) of foods has become an increasing concern in recent years, with lemon juice as a popular target. In this work, an optimized preparation procedure for the isolation of citric acid from lemon juice was validated using elemental analyzer-isotope ratio MS (EA-IRMS) to detect adulteration with exogenous citric acid. Additionally, 69 imported lemon juice samples were evaluated using combustion module-cavity ring down spectrometry (CM-CRDS) and compared with the well-established EA-IRMS.

Quantitative Determination of Arsenic Species from Fruit Juices Using Acidic Extraction with HPLC-ICPMS.

Throughout the US Food and Drug Administration's routine monitoring of various juice samples for elemental contaminants, a limited number of samples exhibited unexpected behavior related to the arsenic content. Juice samples were subjected to total arsenic determination and those containing arsenic > 10 μg kg were subjected to arsenic speciation analysis using FDA Elemental Analysis Manual (EAM) 4.10 method (AOAC First Action Method 2016.

Direct Comparison of Cavity Ring Down Spectrometry and Isotope Ratio Mass Spectrometry for Detection of Sugar Adulteration in Honey Samples.

In the last several years, economically motivated adulteration (EMA) of foods including honey has received increased attention. The addition of inexpensive sweeteners such as high fructose corn syrup or cane sugar to honey is still encountered despite scientific methods that can routinely detect this type of adulteration. The standard method for detection of these adulterants utilizes isotope ratio mass spectrometry (IRMS); however, this technique requires an elevated degree of technical knowledge for operation as well as a high cost for purchase and maintenance.

Matrix Extension and Multilaboratory Validation of Arsenic Speciation Method EAM §4.10 to Include Wine.

A multilaboratory validation (MLV) was performed to extend the U.S. Food and Drug Administration's (FDA) analytical method Elemental Analysis Manual (EAM) §4.

Evaluation of selenium in dietary supplements using elemental speciation.

Selenium-enriched dietary supplements containing various selenium compounds are readily available to consumers. To ensure proper selenium intake and consumer confidence, these dietary supplements must be safe and have accurate label claims. Varying properties among selenium species requires information beyond total selenium concentration to fully evaluate health risk/benefits A LC-ICP-MS method was developed and multiple extraction methods were implemented for targeted analysis of common "seleno-amino acids" and related oxidation products, selenate, selenite, and other species relatable to the quality and/or accuracy of the labeled selenium ingredients.

Arsenic metabolism by human gut microbiota upon in vitro digestion of contaminated soils.

Background: Speciation analysis is essential when evaluating risks from arsenic (As) exposure. In an oral exposure scenario, the importance of presystemic metabolism by gut microorganisms has been evidenced with in vivo animal models and in vitro experiments with animal microbiota. However, it is unclear whether human microbiota display similar As metabolism, especially when present in a contaminated matrix.

Disruption of the arsenic (+3 oxidation state) methyltransferase gene in the mouse alters the phenotype for methylation of arsenic and affects distribution and retention of orally administered arsenate.

The arsenic (+3 oxidation state) methyltransferase (As3mt) gene encodes a 43 kDa protein that catalyzes methylation of inorganic arsenic. Altered expression of AS3MT in cultured human cells controls arsenic methylation phenotypes, suggesting a critical role in arsenic metabolism. Because methylated arsenicals mediate some toxic or carcinogenic effects linked to inorganic arsenic exposure, studies of the fate and effects of arsenicals in mice which cannot methylate arsenic could be instructive.

Exploring the in vitro formation of trimethylarsine sulfide from dimethylthioarsinic acid in anaerobic microflora of mouse cecum using HPLC-ICP-MS and HPLC-ESI-MS.

Although metabolism of arsenicals to form methylated oxoarsenical species has been extensively studied, less is known about the formation of thiolated arsenical species that have recently been detected as urinary metabolites. Indeed, their presence suggests that the metabolism of ingested arsenic is more complex than previously thought. Recent reports have shown that thiolated arsenicals can be produced by the anaerobic microflora of the mouse cecum, suggesting that metabolism prior to systemic absorption may be a significant determinant of the pattern and extent of exposure to various arsenic-containing species.

Detection of chemical warfare agent degradation products in foods using liquid chromatography coupled to inductively coupled plasma mass spectrometry and electrospray ionization mass spectrometry.

The following work presents the exploration of three chromatographic separations in combination with inductively coupled plasma mass spectrometry (ICP-MS) for the analysis of chemical warfare agent degradation products (CWADPs). The robust ionization of ICP is virtually matrix independent thus enabling the examination of sample matrices generally considered too complicated for analysis by electrospray ionization (ESI) or atmospheric pressure chemical ionization MS with little to no sample preparation. The analysis was focused on detecting CWADPs in food matrices, as they present possible vehicles for terrorist contamination.

Complementary molecular and elemental detection of speciated thioarsenicals using ESI-MS in combination with a xenon-based collision-cell ICP-MS with application to fortified NIST freeze-dried urine.

The simultaneous detection of arsenic and sulfur in thioarsenicals was achieved using xenon-based collision-cell inductively coupled plasma (ICP) mass spectrometry (MS) in combination with high-performance liquid chromatography. In an attempt to minimize the (16)O(16)O(+) interference at m/z 32, both sample introduction and collision-cell experimental parameters were optimized. Low flow rates (0.

Determination of organophosphorus fire retardants and plasticizers in wastewater samples using MAE-SPME with GC-ICPMS and GC-TOFMS detection.

Determination of organophosphorus fire retardants and plasticizers at trace levels in wastewater is described. In this work, microwave assisted extraction (MAE) and solid-phase microextraction (SPME) are used for sample preparation to extract and preconcentrate the analytes, followed by analysis by gas chromatography coupled to inductively coupled plasma mass spectrometry (GC-ICP-MS) for phosphorus-specific detection. Gas chromatography coupled to time of flight mass spectrometry (GC-TOF-MS) was used to confirm the organphosphorus fire retardants in wastewater.

Selenium volatiles as proxy to the metabolic pathways of selenium in genetically modified Brassica juncea.

In this study we demonstrate that the headspace selenium volatiles could be used as proxy to the metabolic pathways in the Se-accumulator plant Brassica juncea. The selenium metabolic pathways in wild type plants are compared to those of several genetically modified cultures. Complementary use of atomic and molecular mass spectrometric techniques also allowed for identification of yet unreported minor headspace Se-containing volatiles such as CH3SeSeSeCH3, CH3SeSSeCH3, and CH3SeCH2CH3.

Selenium speciation in Agaricus bisporus and Lentinula edodes mushroom proteins using multi-dimensional chromatography coupled to inductively coupled plasma mass spectrometry.

In this study, selenium species from Se containing proteins in mushrooms (Agaricus bisporus and Lentinula edodes) were investigated with size-exclusion liquid chromatography coupled to UV and inductively coupled plasma mass spectrometry (ICP-MS). Different protein extraction protocols were investigated. Variability of the fractionation patterns with three extraction media (0.