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A rapid, sensitive and precise method for the determination of bromate (BrO3(-)), nitrate (NO3(-)) and nitrite (NO2(-)) in drinking water was developed with Ultra performance Liquid Chromatography-Mass Spectrometry (UPLC-ESI/MS). The elution of BrO3(-), NO3(-) and NO2(-) was attained in less than two minutes in a reverse phase column. Quality parameters of the method were established; run-to-run and day-to-day precisions were3% when analysing standards at 10 µg L(-1). The limit of detection was 0.04 µg NO2(-) L(-1) and 0.03 µg L(-1) for both NO3(-)and BrO3(-). The developed UPLC-ESI/MS method was used to quantify these anions in metropolitan water from Saudi Arabia (Jeddah, Dammam and Riyadh areas) and commercial bottled water (from well or unknown source) after mere filtration steps. The quantified levels of NO3(-) were not found to pose a risk. In contrast, BrO3(-) was found above the maximum contaminant level established by the US Environmental Protection Agency in 25% and 33% of the bottled and metropolitan waters, respectively. NO2(-) was found at higher concentrations than the aforementioned limits in 70% and 92% of the bottled and metropolitan water samples, respectively. Therefore, remediation measures or improvements in the disinfection treatments are required. The concentrations of BrO3(-), NO3(-) and NO2(-) were mapped with Principal Component analysis (PCA), which differentiated metropolitan water from bottled water through the concentrations of BrO3(-) and NO3(-) mainly. Furthermore, it was possible to discriminate between well water; blend of well water and desalinated water; and desalinated water. The point or source (region) was found to not be distinctive.

In the present work, a rapid and sensitive ultra performance liquid chromatography-mass spectrometry method has been proposed for the analysis of capsaicinoids (nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin) present in different Capsicum samples. Extraction of capsaicinoids was carried out by liquid‐liquid extraction using ethanol as an extracting solvent, while the chromatographic separation was achieved by reversed phase C18 column with gradient mobile phase (solvent A: acetonitrile and solvent B: water with 0.1% formic acid). Under the optimum experimental conditions, the linear ranges were 0.5‐50 g/g with correlation coefficient (r 2 ) >0.999 for each capsaicinoids and detection limits were 0.15, 0.05, 0.06, 0.2, and 0.1 g/g for nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin, respectively. Runto-run and day-to-day precisions of the method with relative standard deviations

Bromate is a byproduct formed as a result of disinfection of bromide-containing source water with ozone or hypochlorite. The International Agency for Research on Cancer has recognized bromate as a possible human carcinogen, thus it is essential to determine in drinking water. Present work highlights a development of sensitive and fast analytical method for bromate determination in drinking water by using ultraperformance liquid chromatography-tandem mass spectrometry. The quality parameters of the developed method were established, obtaining very low limit of detection (0.01 ng/mL), repeatability and reproducibility have been found to be less than 3% in terms of relative standard deviation when analyzing a bromate standard at 0.05 μg/mL with 0.4 min analysis time. Developed method was applied for the analysis of metropolitan and bottled water from Saudi Arabia; 22 samples have been analyzed. Bromate was detected in the metropolitan water samples (from desalinization source) at concentrations ranging between 3.43 and 75.04 ng/mL and in the bottled water samples at concentrations ranging between 2.07 and 21.90 ng/mL. Moreover, in comparison to established analytical methods such as liquid chromatography-tandem mass spectrometry, the proposed method was found to be very sensitive, selective and rapid for the routine analysis of bromate at low level in drinking water.

Beclin-1 has a central role in the regulation of autophagy. Barrett's esophagus (BE) is associated with a significantly increased risk for the development of esophageal adenocarcinoma (EAC). In the current study, we evaluated the role of Beclin-1 and autophagy in the EAC. Biopsies obtained from patients with BE and EAC, tissues from a rat model of BE and EAC, and esophageal cell lines were evaluated for the expression of Beclin-1 by immunohistochemistry, immunoblotting, or RT-PCR. Since reflux of bile acids is important in EAC, we also evaluated the effect of exposure to deoxycholic acid (DCA) on autophagy and Beclin-1 expression. Beclin-1 expression was high in squamous epithelium and nondysplastic BE, whereas its expression was low in dysplastic BE and EAC. The same pattern of expression was observed in rat tissues and in esophageal cell lines. Normal esophageal epithelium and HET-1A cells (derived from normal squamous epithelium) show high levels of Beclin-1, but lower levels of Beclin-1 were found in BE and EAC cell lines (CP-A, CP-C, and OE33). Acute exposure to DCA led to increased Beclin-1 expression and increased autophagy as evaluated by electron microscopy and counting percentage of GFP-LC3-positive BE cells with punctate pattern. In contrast, chronic exposure to DCA did not result in the alteration of Beclin-1 levels or autophagy. In summary, these data suggest that autophagy is initially activated in response to bile acids, but chronic exposure to bile acids leads to decreased Beclin-1 expression and autophagy resistance.

High performance liquid chromatography–photodiode array (HPLC–PDA) method has been employed for the simultaneous determination of vitamin C (ascorbic acid) and aspirin (acetylsalicylic acid) in aspirin C effervescent tablets. Chromatographic separation of ascorbic acid (AA) and acetylsalicylic acid (ASA) was performed by reversed–phase using a Betasil C18 column with particle size of 3 µm, 150 mm × 4.6 mm I.D. Optimum separation was achieved in isocratic mode with a binary mobile phase (mixture of water and acetonitrile with 0.1% of formic acid, 75:25, v/v) at a flow rate of 1.0 mL min−1. Recovery of the target compounds was obtained more than 98% with good quality parameters: linearity (r 2 > 0.997), limit of detection (LOD) and limit of quantification (LOQ) values between 1.4 × 10−3 and 5.1 × 10−4 mg mL−1, and intra-day and interday precisions with relative standard deviation (RSD) lower than 2.1%. The content of the analyzed samples ascorbic and acetylsalicylic acid was found 238.23 and 393.49 mg, resp...

Peutz-Jeghers syndrome (PJS) is an autosomal dominant inherited disorder characterized by mucocutaneous melanin pigmentation and gastrointestinal (GI) tract hamartomatous polyps and an increased risk of malignancy. In addition to polyposis, previous studies have reported increased risk of GI and extraGI malignancies in PJS patients, compared with that of the general population. The most common extraintestinal malignancies reported in previous studies are pancreatic, breast, ovarian and testicular cancers.We report the case of a 17-year-old boy who presented with generalized weakness, recurrent sharp abdominal pain and melena, had exploratory laparotomy and ileal resection for ileo-ileal intussusception. Pigmentation of the buccal mucosa was noted. An abdominal computed tomography scan (CT) revealed multiple polyps in small bowel loops. Gastroscopy revealed multiple dimunitive polyps in stomach and pedunculated polyp in duodenum. Colonoscopy revealed multiple colonic polyps. Pathological examination of the polyps confirmed hamartomas with smooth muscle arborization, compatible with Peutz-Jeghers polyps. CT scan guided left para-aortic lymph node biopsy revealed the characteristic features of extra-adrenal para-aortic paraganglioma. Although cases of various GI and extra GI malignancies in PJS patients has been reported, the present case appears to be the first in literature in which the PJS syndrome was associated with asymptomatic extraadrenal para-aortic paraganglioma. Patients with PJS should be treated by endoscopic or surgical resection and need whole-body screening.

Two cation-exchange materials, aluminium tungstate (AT) and sodium dodecyl sulphate–aluminium tungstate (SDS–AT), were synthesized. Both samples were characterized by Fourier transform infrared spectroscopy, X-ray diffraction analysis and scanning electron microscopy. The distribution coefficients for various metal ions on SDS–AT cation-exchange material were performed in different solvent systems. On the basis of distribution coefficient values, the SDS–AT cation-exchange material was found to be selective for the very toxic metal ion, Cr3+. The hybrid cation-exchange material offered a variety of technological opportunities for quantitative determination and separation of Cr3+ from synthetic mixtures of metal ions. Some binary and ternary separations of metal ions; viz., Cd2+–Cr3+, Zn2+–Cr3+, Cu2+–Cr3+, Pb2+–Cr3+, Mg2+–Pb2+–Cr3+ and Mg2+–Cd2+–Cr3+, were performed using a packed column of this material.

The preparation of a laboratory reference material (LRM) for the determination of naturally occurring heterocyclic amines (HAs) in processed foods is presented in this work. A LRM was prepared from raw chicken breast meat, which was fried under controlled cooking temperature and time. The cooked meat was ground, lyophilised, sieved, homogenised, bottled, and labelled. The HAs DMIP, PhIP, MeIQx, 4,8-DiMeIQx, Norharman and Harman were analysed in the LRM. Homogeneity and stability studies of the bulk LRM were carried out and no statistical differences were observed in the content of the studied HAs in between-bottle and within-bottle comparisons at different storage temperatures (-18, +4, +25 and +40 degrees C) and times (1, 3, 6 and 9 months) by means of HAs determination and analysis of the results. Consequently, the material can be considered homogeneous and stable and can be used in intercomparison exercises for the determination of HAs as well as for quality control purposes in the routine analysis of HAs in foodstuffs. This is the first LRM for the analysis of HAs where these analytes were naturally formed in the material.

Heterocyclic amines (HAs) are potent mutagens formed during heat-processing of proteinaceous food. PhIP is the most ubiquitous and abundant mutagenic HA. In this study several offal products (beef liver, lamb kidney and beef tongue) have been thermally processed and analysed for HAs for the first time. Norharman and harman were the amines most abundant, found at concentrations below 2 ng g−1. PhIP was only formed up to 0.12 ng g−1. Among the rest of HAs analysed, only DMIP, MeIQx and 4,8-DiMeIQx were detectable in cooked kidney and tongue up to 0.25 ng g−1. The influence of cooking additives on HAs formation was evaluated, finding higher levels of norharman and harman, up to 8.87 ng g−1, in liver processed with additives, whereas similar levels of the rest of HAs were found in these samples. The low amounts of HAs found after the prolonged thermal treatments over 200 °C indicates that offal products are among the types of meat that produce lowest exposure to HA.

Heterocyclic amines (HAs) were analysed in meat extract samples using a new method based on pressurised liquid extraction (PLE) and liquid chromatography-tandem mass spectrometry. This method combines the use of a pressurised fluid with a triple quadrupole MS/MS system, resulting in benefits from both systems: high extraction efficiency and sensitivity. The effects of solvent type and PLE operational parameters, such as temperature and extraction time, were studied to obtain maximum recovery of the analytes with minimum contamination. HA extraction was best achieved using dichloromethane/acetone (50/50, v/v) at 80 degrees C for 10 min. Recoveries ranged from 45% to 79% with good quality parameters: limit of detection values between 0.02 and 1 ng g(-1), linearity (r(2)>0.997), and run-to-run and day-to-day precisions with relative standard deviations lower than 13% achieved at both low (0.20 microg g(-1)) and medium (1.0 microg g(-1)) concentrations. This method reduces sample manipulation and total extraction time by nearly four-fold compared to conventional solid phase extraction. The optimised method was validated using laboratory reference material based on a meat extract, and was successfully applied to HA analysis in several cooked beef samples.

Activated carbon was prepared from date pits via chemical activation with H3PO4. The effects of activating agent concentration and activation temperature on the yield and surface area were studied. The optimal activated carbon was prepared at 450 °C using 55 % H3PO4. The prepared activated carbon was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric-differential thermal analysis, and Brunauer, Emmett, and Teller (BET) surface area. The prepared date pit-based activated carbon (DAC) was used for the removal of bromate (BrO3 −). The concentration of BrO3 − was determined by ultra-performance liquid chromatography-mass tandem spectrometry (UPLC-MS/MS). The experimental equilibrium data for BrO3 − adsorption onto DAC was well fitted to the Langmuir isotherm model and showed maximum monolayer adsorption capacity of 25.64 mg g−1. The adsorption kinetics of BrO3 − adsorption was very well represented by the pseudo-first-order equation. The analytical application of DAC for the analysis of real water samples was studied with very promising results. This project was funded by the National Plan for Science, Technology and Innovation (MAARIFAH), King Abdulaziz City for Science and Technology, Kingdom of Saudi Arabia (Award Number 12-WAT3138-02).

Heterocyclic amines (HCAs) are known to be suspected human carcinogens produced by high-temperature cooking of protein-rich foods such as meat and fish. In the present study, the influence of numerous food condiments on the formation of HCAs in cooked chicken was investigated. Chicken samples were subjected to pan-frying under controlled temperature. The levels of HCAs DMIP, MeIQx, 4,8-DiMeIQx, PhIP, harman and norharman were found to be between 0.93 and 27.52 ng g(-1), whereas IQ, MeIQ, AαC, MeAαC, Trp-P-1 and Trp-P-2 were found either below the limit of quantification or not detected in the control sample. Nevertheless, for samples cooked using food condiments, the amounts of HCAs (DMIP, MeIQx, 4,8-DiMeIQx and PhIP) were between 0.14 and 19.57 ng g(-1); harman and norharman were detected at higher concentrations up to 17.77 ng g(-1) while IQ and MeIQ were at levels below the limit of quantification; and AαC, MeAαC, Trp-P-1 and Trp-P-2 were not detected in any of the samples. The outcomes revealed that the formation of HCAs (except harman and norharman) diminished after the addition of food condiments. Edible oil contributed to the highest levels of HCA formation, followed by garlic, paprika, pepper and tomato.

History and Introduction of UPLC/MS Mu. Naushad, Mohammad Rizwan Khan, and Zeid Abdullah ALOthman UHPLC-MS(/MS) Analysis of Pesticides in Food Paolo Lucci, Rosa Busquets, and Oscar Nunez Ultra-High-Performance Liquid Chromatography in Food Metabolomics: Food Quality and Authenticity Cristina C. Jacob and H. Gallart-Ayala UHPLC-MS-Based Methods for the Study of Foodborne Carcinogens Lubinda Mbundi and Rosa Busquets Ultra-Performance Liquid Chromatography-Mass Spectrometry for the Determination of Capsaicinoids in Capsicum Species Saikh Mohammad Wabaidur Applications of UPLC-MS/MS for the Quantification of Folate Vitamers Maria V. Chandra-Hioe, Jayashree Arcot, and Martin P. Bucknall UPLC-MS/MS Analysis of Heterocyclic Amines in Cooked Food Mohammad Rizwan Khan and Mu. Naushad Determination of Avocado Fruit Metabolites by UHPLC-MS: Complementarity with Other Analytical Platforms Elena Hurtado-Fernandez, Maria Gomez-Romero, Tiziana Pacchiarotta Oleg A. Mayboroda, Alegria Carrasco-Pancorbo, and Alberto Fernandez-Gutierrez UHPLC-MS in Virgin Olive Oil Analysis: An Evolution toward the Rationalization and Speed of Analytical Methods Aadil Bajoub, Alegria Carrasco-Pancorbo, Noureddine Ouazzani, and Alberto Fernandez-Gutierrez Vitamin Analysis in Food by UPLC-MS Ahmad Aqel, Kareem Yusuf, Asma'a Al-Rifai, and Zeid Abdullah ALOthman UPLC-MS as an Analytical Tool for the Determination of Aflatoxins in Food Kareem Yusuf, Ahmad Aqel, Ayman Abdel Ghfar, and Zeid Abdullah ALOthman Determination of Perfluorochemicals in Food and Drinking Water Samples Using UHPLC-MS Technique Fabio Gosetti, Eleonora Mazzucco, Maria Carla Gennaro, and Emilio Marengo Determination of Acrylamide in Foodstuffs Using UPLC-MS Ayman Abdel Ghfar and Ibrahim Hotan Alsohaimi Determination of Procyanidins and Alkaloids in Cocoa and Biological Samples by Ultra-High-Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry Alba Macia, Maria Jose Motilva, and Nadia Ortega Ultra-Performance Liquid Chromatography-Mass Spectrometry and Its Application toward the Determination of Lactose Content in Milk Mahamudur Islam Fast and Reliable Analysis of Phenolic Compounds in Fruits and Vegetables by UHPLC-MS M. I. Alarcon-Flores, R. Romero-Gonzalez, J. L. Martinez Vidal, and A. Garrido Frenich

Nanoparticles, bisphenols, mycotoxins, and brominated flame retardants are highly relevant species toxicologically that can contaminate food and drink through intentional administration or unintentionally from their migration from diverse sources such as packaging materials, cooking utensils, environmental contamination, and fungal activity. Although seemingly different, these contaminants share the common feature of being difficult to isolate and analyze in food. This chapter highlights the different challenges associated with the determination of the study toxins in food and drink and discusses current methods of analysis as well as methods and strategies to overcome the analytical challenges.

Ultra performance liquid chromatography coupled to mass spectrometry was used for the simultaneous separation and determination of reducing monosaccharides (fructose and glucose), a non-reducing disaccharide (sucrose) and oligosaccharides (kestose and nystose) in HILIC mode. The chromatographic separation of all saccharides was performed on a BEH amide column using an acetonitrile-water gradient elution. The detection was carried out using selected ion recording (SIR) acquisition mode. The validation of the proposed method showed that the limit of detection and limit of quantification values for the five analyzed compounds were in the range of 0.25-0.69μg/mL and 0.82-3.58μg/mL, respectively; while the response was linear in the range of 1-50μg/mL. The developed method showed potential usefulness for a rapid and sensitive analysis of underivatized saccharides and was used for determination of sugars in three date samples (Sefri, Mabroom, Ghassab) which were soxhlet extracted by ethanol.

In the present study, De-Acidite FF-IP resin was used to remove a highly toxic and persistent organophosphorus pesticide (malathion) from the aqueous solution. Batch experiments were performed as a function of various experimental parameters such as effect of pH (2–10), contact time (10–120 min), resin dose (0.05–0.5 g), initial malathion concentration (0.5–2.5 µg mL −1 ) and temperature (25–65 °C). The concentration of malathion was determined using a sensitive, selective and rapid ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method. The uptake rate of malathion on De-Acidite FF-IP resin was rapid and equilibrium established within 40 min. Kinetics studies showed better applicability for pseudo-second-order model. The equilibrium data was fitted to Langmuir and Freundlich isotherm models and the isotherm constants were calculated for malathion. The values of thermodynamic parameters (Δ G 0 , Δ H 0 and Δ S 0 ) were computed from the Van't Hoff plot of ln K C vs. 1/ T which showed that the adsorption of malathion was feasible, endothermic and spontaneous. The regeneration studies were carried out which demonstrated a decrease in the recovery of malathion from 95% to 68% after five consecutive cycles. Breakthrough and exhaustive capacities of malathion were found to be 1.25 mg g −1 and 3.5 mg g −1 , respectively.

In the present study, the effect of various natural food condiments (garlic, ginger, pepper, tomato and onion) on the formation of heterocyclic amines (HAs) in cooked camel meat was studied. In control sample, the amount of HAs MeIQx, 4,8-DiMeIQx and PhIP were obtained between 2.10 and 5.22 ng/g, while, MeIQ and IQ were found less than quantification limit. The camel meat cooked with different food condiments, the HAs were found in lesser amounts. MeIQx, 4,8-DiMeIQx and PhIP were detected from 0.42 to 2.83 ng/g, however, MeIQ and IQ were not indentified in any analyzed samples. Consequently, camel meat cooked by various food condiments illustrates the capability to reduce the HAs formation. Such information may be elucidated because of the presence of antioxidants in such condiments which might have pro-oxidative effects with the subsequent formation of peroxyl radicals or by the scavenging of oxygen or free radicals. Practical Applications This is the first study relating to the inhibition of HAs by means of some common food condiments in cooked camel meat. In this work, five HAs such as MeIQx, 4,8-DiMeIQx, PhIP, MeIQ and IQ have been studied in camel meat samples thermally processed with or without food condiments. Our results evidently demonstrate that the formation of HAs in cooked camel meat is highly affected by using food condiments. The current study also illustrates that the concentrations of HAs can be kept at low levels by cooking the meat that include food condiments. The obtained results could be used to estimate the human intake of HAs either in Saudi Arabia or global and supplied to the search of good food condiments that reduce the threat of exposure to HAs, and thus to advance the food security and quality.

In the present work, a rapid and sensitive ultra performance liquid chromatography-mass spectrometry method has been proposed for the analysis of capsaicinoids (nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin) present in different Capsicum samples. Extraction of capsaicinoids was carried out by liquid-liquid extraction using ethanol as an extracting solvent, while the chromatographic separation was achieved by reversed phase C(18) column with gradient mobile phase (solvent A: acetonitrile and solvent B: water with 0.1% formic acid). Under the optimum experimental conditions, the linear ranges were 0.5-50 μg/g with correlation coefficient (r(2) )0.999 for each capsaicinoids and detection limits were 0.15, 0.05, 0.06, 0.2, and 0.1 μg/g for nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin, respectively. Run-to-run and day-to-day precisions of the method with relative standard deviations1.5% were achieved for all analyzed capsaicinoids. The robustness of the method was determined by utilizing different injection volumes of the extracts. Furthermore, to validate the system robustness, a run of high number of capsaicinoids present in different varieties of Capsicum samples was performed in this study. All the capsaicinoids were separated in a time of less than 9 min by employing the proposed method.

Bromate is a byproduct formed as a result of disinfection of bromide-containing source water with ozone or hypochlorite. The International Agency for Research on Cancer has recognized bromate as a possible human carcinogen, thus it is essential to determine in drinking water. Present work highlights a development of sensitive and fast analytical method for bromate determination in drinking water by using ultraperformance liquid chromatography-tandem mass spectrometry. The quality parameters of the developed method were established, obtaining very low limit of detection (0.01 ng/mL), repeatability and reproducibility have been found to be less than 3% in terms of relative standard deviation when analyzing a bromate standard at 0.05 μg/mL with 0.4 min analysis time. Developed method was applied for the analysis of metropolitan and bottled water from Saudi Arabia; 22 samples have been analyzed. Bromate was detected in the metropolitan water samples (from desalinization source) at concentrations ranging between 3.43 and 75.04 ng/mL and in the bottled water samples at concentrations ranging between 2.07 and 21.90 ng/mL. Moreover, in comparison to established analytical methods such as liquid chromatography-tandem mass spectrometry, the proposed method was found to be very sensitive, selective and rapid for the routine analysis of bromate at low level in drinking water.

The aim of this study is to assess whether the effect of gender on the excessive daytime sleepiness (EDS) is influenced by two confounders (age and hours of sleep per night). A cross-sectional study was conducted at King Abdulaziz Medical City-Riyadh (KAMC-R). A total of 2095 respondents answered a questionnaire that included questions regarding gender, age, hours of sleep per night, and daytime sleepiness using the Epworth Sleepiness Scale (ESS). The prevalence of EDS was 20.5% (females 22.2%, males 19.5%, p-value = 0.136). The EDS did not differ between genders, age groups, or hours of sleep per night (

Bromate (BrO3−) is a possible human carcinogen which is formed as a bromide containing source water ozone disinfection by-product. Thus, BrO3− is subject to assess its threat to humans. In the present study, an ultra performance liquid chromatography-electrospray ionization mass spectrometry method has been developed for the quantitative analysis of BrO3− in non-alcoholic beer. The chromatographic separation of both transitions 81BrO3− and 79BrO3− (isotope contributions of 79Br and 81Br) was carried out and achieved in 0.9999), precision (repeatability and reproducibility in terms of relative standard deviation)

Excess of nutrient load can cause water eutrophication and be harmful to humans. While nitrogen is an important nutrient for crops, its introduction into the soil with fertilizers containing nitrate (NO3−) has been a major source of water pollution and monitoring NO3− has become necessary. In the present work, an ultra performance liquid chromatography-mass spectrometry method has been developed for the rapid quantification of NO3− in drinking water with reversed phase chromatography using a Waters Acquity BEH C18 (50 mm × 2.1 mm i.d., 1.7 μm particle size) column and a triple quadrupole mass spectrometer operating in Single Ion Recording mode. The quality parameters of the developed method were established, obtaining a limit of detection of 0.02 μg L−1; linearity (r2 > 0.999) over a concentration range covering 3 orders of magnitude; high precision, with repeatability and reproducibility lower than 3% (n = 5) in terms of relative standard deviation when analyzing a standard (0.05 mg NO3− L−1) and unspiked drinking water samples with levels of NO3− of 1 μg L−1 (metropolitan water) and 3 mg L−1 (bottled water). These quality parameters show that the proposed method improves the performance of conventional analytical methods used for the analysis of NO3−. This method has been applied successfully for determination of NO3− in metropolitan and bottled water from the Kingdom of Saudi Arabia; a total of 25 samples have been analyzed where NO3− was found to be present from levels below the limit of detection to 6.49 mg L−1.

Background and Aims: Autophagy is a normal physiological mechanism for the degradation of cellular proteins and organelles. Excessive autophagy induced by cellular stress leads to cell death. However, the exact role of autophagy in cancer is not completely clear. Beclin1 plays a central role in the regulation of autophagy. The major goal of our study was to evaluate the role of Beclin-1 and autophagy and the effect of bile acids in the esophageal carcinogenesis. Barrett's esophagus (BE) is a premalignant lesion of distal esophagus associated with an increased risk for the development of esophageal adenocarcinoma (EAC). Methods: Beclin-1 expression was evaluated using immunohistochemistry, immunoblotting, or RTPCR in (1) biopsies obtained from 62 patients with BE or EAC, (2) tissues from a rat model of BE and EAC, and (3) esophageal cell lines. Since reflux of bile acids is important in esophageal carcinogenesis, the effect of acute and chronic exposure to deoxycholic acid (DCA) on autophagy and Beclin-1 expression was evaluated. Autophagy was assessed by electron microscopy or by transfection with GFP-LC3 plasmid and calculating the percentage of GFP-LC3 positive cells with punctuate pattern. Results: Our studies using human biopsies and rat tissues showed that Beclin-1 expression was high in squamous epithelium, while its expression was low in BE and EAC. A similar pattern was observed in esophageal cell lines. HET-1A cells (derived from normal squamous epithelium) showed high levels of Beclin-1, but lower levels of Beclin-1 were found in BE cells (CP-A, CP-C) and EAC cells (OE33 cells). Acute exposure to DCA led to increased Beclin-1 expression and increased autophagy in CP-A cells. In contrast, chronic exposure to DCA did not result in any alteration of Beclin-1 or autophagy. To demonstrate that Beclin-1 plays central role in autophagy we used siRNA to decrease Beclin-1 expression and then autophagy was evaluated after treatment with DCA. No increase in autophagy was detected compared to untreated control CP-A cells. Conclusions: In summary, our data suggests that autophagy is initially activated in response to bile acids, but chronic exposure to bile acids leads to decreased Beclin-1 expression and autophagy resistance. We propose that autophagy resistance in combination with apoptosis resistance induced by chronic exposure to bile acids contributes to EAC development.

Bisphenol A (BPA) is a hazardous contaminant demonstrating endocrine disrupting properties, and assumed to be involved in the pathogenesis of various cancer diseases for instance prostate, lung and breast cancer. The objective of the present study was to estimate the BPA amounts in carbonated beverages from the Saudi Arabian market for the first time using an authenticated technique based on solid-phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry. A total of thirty-four carbonated beverages of different flavors, origin and packaging materials were studied. The beverage production periods were from February 2018 to July 2018 containing volume (250-1000 mL), packaging materials were of canned, glass and polyethylene terephthalate (PET) plastic. BPA amounts in canned (0.64-11.41 µg/L), glass bottled (1.92-29.56 µg/L) and PET plastic bottled (0.37-21.83 µg/L) were obtained with recovery (97.64-99.96%). Relatively, glass bottled has offered higher amounts of BPA compared to PET plastic bottled and canned samples. The unforeseen presence of BPA especially in glass bottled emphasizes the ubiquity of such compound beside the food fabrication chain, far off to the food packaging materials. Thus, a further knowledge on BPA amounts in glass bottled samples, in addition to threat assessment studies, is essential to defend human health.