Roasted Rye as a Coffee Substitute: Methods for Reducing Acrylamide.

Acrylamide is assumed to be a potential carcinogen, and reference values have therefore been implemented in EU legislation. Thus, the food industry needs to reduce the acrylamide content in consumer products to the lowest possible value. In this study, roasted rye was evaluated for its suitability as a coffee substitution product with respect to its acrylamide content. The influence of process modifiers, free asparagine content, storage, and rye type on the final content of acrylamide was investigated. Changes in carbohydrate composition and brightness caused by the roasting process were described. Sample analysis was conducted via GC-MS and HPLC-CAD. Existing methods were adapted to roasted rye as the sample matrix. CaCl2 and asparaginase treatment as well as pH adjustments prior to roasting did not prove to reduce the acrylamide content. A significantly (* p < 0.027) lower free asparagine content in the raw material resulted in a lower formation of acrylamide in the final product. The acrylamide content significantly decreased (**** p < 0.0001) after 3 (1100 ± 18 µg kg-1) and 6 (490 ± 7 µg kg-1) months of long-term storage. Only samples stored for 6 months (490 ± 7 µg kg-1) met the EU acrylamide content requirements (<500 µg kg-1) for grain-based coffee substitution products.

Quantification ethyl carbamate in wines using reaction-assisted-extraction with 9-xanthydrol and detection by heart-cutting multidimensional gas chromatography-mass spectrometry.

9-Xanthydrol was introduced as an assisted-extraction-reagent to quantify ethyl carbamate (EC) in wines by heart-cutting multidimensional gas chromatography coupled with mass spectrometry (MDGC-MS). 9-Xanthydrol could help to increase the extraction efficiency, because it could react with ethyl carbamate to form the low-polar product, which facilitated the transfer of ethyl carbamate into organic phase. Then the reaction product was decomposed in high temperature, so ethyl carbamate could be obtained again in injector port. Heart-cutting multidimensional gas chromatography coupled with mass spectrometry was used not only for avoiding 9-xanthydrol interference but also for getting a larger volume injector, higher sensitivity and lower limit of detection. The method was optimized and validated in terms of sample volume, sodium chloride, the acid concentration, the 9-xanthydrol concentration and the reaction time. Good linear relationship (R2 = 0.9998) over the concentration range of 2.00 µg L-1 - 200.00 µg L-1 was obtained. The limit of detection (LOD, 0.02 µg L-1) and quantification (LOQ, 0.10 µg L-1) were lower than previously reported. The RSDs of precision (repeatability and reproducibility) were lower than 8.15%, and the recovery (96.17-99.25%) and accuracy (99.21-110.93%) were validated as well. This methodology was applied to the quantification of ethyl carbamate in several different fermented wines with values ranging from 13.05 to 155.20  µg L-1.

Determination of hydroxyurea in human plasma by HPLC-UV using derivatization with xanthydrol.

A simple and rapid high performance liquid chromatography (HPLC) method using ultraviolet (UV) detection was developed to determine hydroxyurea (HU) concentration in plasma sample after derivatization with xanthydrol. Two hundred microliters samples were spiked with methylurea (MeU) as internal standard and proteins were precipitated by adding methanol. Derivatization of HU and MeU was immediately performed by adding 0.02M xanthydrol and 1.5M HCl in order to obtain xanthyl-derivatives of HU and MeU that can be further separated using HPLC and quantified using UV detection at 240nm. Separation was achieved using a C18 column with a mobile phase composed of 20mM ammonium acetate and acetonitrile in gradient elution mode at a flow rate of 1mL/min. The total analysis time did not exceed 18min. The method was found linear from 5 to 400µM and all validation parameters fulfilled the international requirements. Between- and within-run accuracy error ranged from -4.7% to 3.2% and precision was lower than 12.8%. This simple method requires small volume samples and can be easily implemented in most clinical laboratories to develop pharmacokinetics studies of HU and to promote its therapeutic monitoring.

A DFT study of the formation of xanthydrol motifs during electrophilic poly(aryl ether ketone) synthesis.

The reaction pathway of the cyclization of 2-phenoxybenzophenone into 9-phenyl-9H-xanthen-9-ol in the presence of acid and an excess of AlCl33 was studied using density functional theory. This type of reaction is known to occur during the Friedel-Crafts polycondensation of poly(aryl ether ketones) following the undesired benzoylation of nucleophilic positions ortho- to the growing polymer's ether groups. The formed defect acts as an undesired terminator of the polymer chain, causing severe problems in the polymer's melt state. A branched, multistep mechanism reminiscent of the Friedel-Crafts acylation reaction is discovered; the reaction starts with the protonation of the carbonyl oxygen, followed by intramolecular electrophilic attack on the carbonyl carbon that determines the turnover frequency of the catalytic cycle and ends by deprotonation of the Wheland intermediate.

Ultra trace level determinations of acrylamide in surface and drinking water by GC-MS after derivatization with xanthydrol.

A sensitive GC-MS method has been established for the determination of acrylamide in surface and drinking water based on derivatization with xanthydrol. Deuterated acrylamide (acrylamide-d3 ) was chosen as the internal standard for analyzing the water sample. The derivatization of acrylamide was performed directly in water, and the best reaction conditions (xanthydrol of 1.6 mM, HCl concentration of 0.05 M, reaction for 30 min at ambient temperature) were established by variation of parameters. Under the established conditions, the detection and quantification limits were 3.0 and 9.7 ng/L, respectively, and the interday RSD was less than 8% at concentrations of 20 and 100 ng/L.

Trace level determinations of carbamate pesticides in surface water by gas chromatography-mass spectrometry after derivatization with 9-xanthydrol.

A sensitive and selective gas chromatographic mass spectrometric method, based on derivatization with 9-xanthydrol, has been established for the simultaneous determination of five carbamate pesticides (carbaryl, carbofuran, metolcarb, isoprocarb and ethiofencarb) in surface water. 4-Bromo-3,5-dimethylphenyl-N-methylcarbamate was chosen as the internal standard for analyzing water samples. The derivatization of carbamates was performed directly in water and the reaction conditions (9-xanthydrol of 50.0mM, HCl concentration of 0.05M, reaction for 60min at 60°C) were established through the optimization of various parameters. Under the established conditions, the limits of quantification were in the range of 0.007-0.028µg/L, and the intra- and inter-day relative standard deviation were each less than 15% at concentrations of 0.1, 1.0 and 10µg/L. None of the carbamate pesticides were detected in any of the sixteen surface waters analyzed.

Determination of trace levels of acetamide, propanamide, and butyramide in surface and drinking water using gas chromatography-mass spectrometry after derivatization with 9-xanthydrol.

A sensitive gas chromatographic mass spectrometric (GC-MS) method has been established for the simultaneous determination of acetamide (AA), propanamide (PA), and butyramide (BA) in surface and drinking water based on derivatization with 9-xanthydrol. Deuterated acrylamide was chosen as the internal standard for analyzing the water sample. The derivatization of AA, PA, and BA was performed directly in water and the reaction conditions (10.0-mM 9-xanthydrol, 0.5-M HCl, 20-min reaction time, and ambient temperature) were established. Under these conditions, the detection limit of the analytes was 0.03 µg L(-1), and the interday relative standard deviation was less than 16% at concentrations of 1.0, 5.0 and 10.0 µg L(-1). The proposed GC-MS method enables the reliable analysis of trace AA, PA, and BA in environmental water.