Identification and quantification of the osmodiuretic mannitol in urine for sports drug testing using gas chromatography-mass spectrometry

Exploring the Use of Polyols, Corn, and Beet Juice for Decreasing the Freezing Point of Brine Solution for Deicing of Pavements

Deicing of pavements is essential to ensure safe and timely movement of traffic in geographical locations where snow and ice events are anticipated. State and local municipalities employ brine solution with 23.3 wt% sodium chloride (NaCl) available in the form of rock salt to deice the pavements. Unlike water, the brine solution does not freeze until the temperature falls below −21.0 °C, i.e., the freezing point of water is depressed by −21.0 °C with the addition of 23.3 wt% NaCl. The depressed freezing point of the brine solution plays a key role in deicing pavements. Unfortunately, a further increase in rock salt content does not lower the freezing point of the brine solution. In this study, different combinations of agricultural products such as polyols including sorbitol, maltitol, and mannitol in brine (23.3 wt% of NaCl in water), and NaCl-juice (corn and beet juice) were investigated to achieve freezing point depressions below −21.0 °C for potential deicing applications in extremely cold areas. Different weight fractions of polyols-brine solutions ranging from 7.14% to 27.77% were considered, and corresponding freezing points were determined. While the sorbitol-brine solution exhibited the lowest freezing point of −38.1 °C at a higher concentration, the maltitol-brine solution exhibited a freezing point of −35.6 °C at the same concentration. Based on the °Brix value, beet juice had almost three times more soluble solids and a lower freezing point compared to corn juice. Adding 23.3 wt% of NaCl in 70% corn juice lowered the freezing point up to −23.5 °C.

Recent advances in the biotechnological production of erythritol and mannitol

Dietary habits that include an excess of added sugars have been strongly associated with an increased risk of obesity, heart disease, diabetes, and tooth decay. With this association in view, modern food systems aim to replace added sugars with low calorie sweeteners, such as polyols. Polyols are generally not carcinogenic and do not trigger a glycemic response. Furthermore, owing to the absence of the carbonyl group, they are more stable compared to monosaccharides and do not participate in Maillard reactions. As such, since polyols are stable at high temperatures, and they do not brown or caramelize when heated. Therefore, polyols are widely used in the diets of hypocaloric and diabetic patients, as well as other specific cases where controlled caloric intake is required. In recent years, erythritol and mannitol have gained increased importance, especially in the food and pharmaceutical industries. In these areas, research efforts have been made to improve the productivity and yield of the two polyols, relying on biotechnological manufacturing methods. The present review highlights the recent advances in the biotechnological production of erythritol and mannitol and summarizes the benefits of using the two polyols in the food and pharmaceutical industries.

Urinary concentrations of AICAR and mannitol in athlete population

Both AICAR and mannitol are prohibited for use in sports, but no decisive criteria that would guide anti-doping laboratories on data interpretation have been established so far. In an attempt to help harmonize reporting and management of analytical findings, reference population data collected for US athletes are presented. Upon analysis of 12 377 samples, mean urinary AICAR concentration was found to be 647 ± 365 ng/mL with median value of 574 ng/mL, 99th percentile at 1786 ng/mL and 99.7th percentile at 2151 ng/mL. Based on these results, we suggest that any sample with AICAR concentration greater than 2000 or 2500 ng/mL be analyzed by carbon isotope ratio mass spectrometry to establish the origin. Urinary mannitol concentrations demonstrate larger variation with the mean value of 72 ± 140 μg/mL and median at 41 μg/mL (n = 6407). While the 99.7th percentile for mannitol was measured to be 1094 μg/mL, the population data alone is not sufficient to suggest a threshold value. It is also shown that the use of mannitol as a sweetener in amounts of up to 20 g per day results in a urinary concentration of about 14 mg/mL. As only intravenous mannitol is prohibited in sports, controlled excretion studies are needed to see whether intravenous administration could in fact be discriminated from dietary intake. An important observation is that mannitol present in mg/mL quantities significantly increases urine specific gravity, which makes a widely accepted normalization approach not applicable.

Plasma volume expanders: use in medicine and detecting misuse in sports

Plasma volume expanders comprise a heterogeneous group of substances used in medicine that are intravenously administered in cases of great blood loss owing to surgery or medical emergency. These substances, however, can also be used to artificially enhance performance of healthy athletes in sport activities, and to mask the presence of others substances. These practices are considered doping, and are therefore prohibited by the International Olympic Committee and the World Antidoping Agency. Consequently, drug testing procedures are essential. The present work provides an overview of plasma volume expanders, assembling pertinent data such as chemical characteristics, physiological aspects, adverse effects, doping and analytical detection methods, which are currently dispersed in the literature.

The analytical chemistry of drug monitoring in athletes

The detection and deterrence of the abuse of performance-enhancing drugs in sport are important to maintaining a level playing field among athletes and to decreasing the risk to athletes' health. The World Anti-Doping Program consists of six documents, three of which play a role in analytical development: The World Anti-Doping Code, The List of Prohibited Substances and Methods, and The International Standard for Laboratories. Among the classes of prohibited substances, three have given rise to the most recent analytical developments in the field: anabolic agents; peptide and protein hormones; and methods to increase oxygen delivery to the tissues, including recombinant erythropoietin. Methods for anabolic agents, including designer steroids, have been enhanced through the use of liquid chromatography/tandem mass spectrometry and gas chromatography/combustion/isotope-ratio mass spectrometry. Protein and peptide identification and quantification have benefited from advances in liquid chromatography/tandem mass spectrometry. Incorporation of techniques such as flow cytometry and isoelectric focusing have supported the detection of blood doping.