Design of a Novel Auxiliary Diagnostic Test for the Determination of Authenticity of Tequila 100% Agave Silver Class Based on Chemometrics Analysis of the Isotopic Fingerprint of the Beverage

The present research shows a robust isotopic ratio characterization of Carbon-13 (δ¹³C_VPDB) in congeneric compounds such as methanol, n-propanol, isoamyl alcohol, ethyl lactate, ethyl acetate, ethanol, and acetaldehyde in representative samples (n = 69) of Tequila 100% agave silver class (TSC), employing gas chromatography/combustion/isotope-ratio mass spectrometry (GC/C/IRMS). From the information obtained, the construction of a radial plot attributable to the isotopic fingerprint of TSC was achieved. With this information, a diagnostic test was designed to determine the authenticity of TSC, comparing alcoholic beverages from other agave species as non-authentic samples. The sensitivity of the test was 94.2%; the specificity was 83.3%. Additionally, non-authentic samples were analyzed that meet all the criteria established in the regulations. The results obtained show that the GC/C/IRMS analytical technique and designed diagnostic test are useful as auxiliary parameters to determine the authenticity of the beverage, thus managing to determine the adulteration or falsification of the product.

Exposure to bisphenol A and breast cancer risk in northern Mexican women

OBJECTIVE

To evaluate the association between BC and urinary concentrations of free-bisphenol A (BPA-F), the biological form of BPA, among women residing in Northern Mexico.

METHODS

The population under study comprised 394 histologically confirmed BC cases and 404 age-matched controls. Women were interviewed face to face about their sociodemographic and reproductive characteristics. BPA-F was determined by high-pressure liquid chromatography equipped with a fluorescence detector (HPLC/FLD). Logistic regression models were used to estimate the adjusted BC risk in relation to BPA-F.

RESULTS

BPA-F geometric mean was significantly higher among cases compared to controls (3.16 μg/L in cases and 2.47 μg/L in controls). A significant adjusted BC odds ratio of 2.31 (95% CI: 1.43-3.74) was estimated for the highest category of BPA-F compared to the lowest category.

CONCLUSION

BPA-F may be an environmental cofactor of BC. Since this is the first report on BPA-F association with BC, our results need to be replicated.

Exposure to bisphenol A and diabetes risk in Mexican women

Bisphenol A (BPA) is an endocrine-disrupting chemical widely used in the production of polycarbonate plastics and epoxy resins, which has been previously linked to diabetes among non-Hispanic populations. As part of a case control study for breast cancer, only controls with BPA information were included in this report. The final sample size comprises 70 self-reported diabetics and 334 non-diabetics. Urinary free bisphenol A (BPA-F) (μg/L) was determined by solid-phase extraction and HPLC/FLD analysis. Logistic regression models were used to evaluate the association between BPA-F and self-reported diabetes. After adjusting by age, urinary BPA-F (4.06-224.53 μg/g creatinine) was associated with diabetes exposure (OR = 1.85; 95% CI 1.04, 3.28) compared with women in the reference category (0.67-4.05 μg/g creatinine). BPA may be an environmental cofactor of diabetes. More studies are needed to confirm this result, especially in Hispanic populations.

Collecting data for several crystals in a single exposure to X-rays

The experimental technique which has been of the greatest importance in revealing the structure of crystals is undoubtedly X-ray diffraction; recently with the CCD detector the time of collection data is most fast, which has given opportunity to explore the option of data collection multiple crystals or twinning crystals of same chemical substance. Considering the Ewald sphere or expression of Bragg's law where it involves the reciprocal lattice in the sphere of reflection and using CrysAlis PRO171 software [1] is possible to identify the number of unit-cells that are present in the material which is composed of multiple crystals (see figure) that have intentionally place in this work. By placing the [1,2-bis(diisopropylphosphanyl)ethane]dichloridonickel(II) (A)[2] and 17β-acetoxy-4,5-secoandrost-3-yn-5-one (B)[3] crystals in the X-ray diffractometer Gemini with Atlas area detector and source of radiation λMo.= 0.7103 to 130 K and collect data for the system of lowest symmetry (2) (laue group: mmm) obtained a total of 15341 reflections in 307 frames and 4 runs with a total time of 2h 17m. Using the lattice wizard tool and Ewald explorer-reciprocal space two groups of data collection is obtained, which the resolve and refine separately R1(obs data) of 0.0255 and 0.0574 for A and B compounds respectively.