Detection and quantification of leached ethylene glycol in biopharmaceuticals by RP-UHPLC.

Biopharmaceuticals are in direct contact with different plastic materials, which can contribute to process-related impurities. Polyethylene terephthalate glycol (PETG) is used for storage and transportation of biopharmaceuticals and it is synthetized from the poly-condensation reaction between ethylene glycol, 1,4-cyclodimethanol and dimethyl terephthalate. PETG bottles are analyzed for such impurities prior to release; however, the nature of the pharmaceutical matrix can extract impurities, so it is important to measure these contaminants in biopharmaceuticals. This study shows a liquid chromatography method for the quantification of ethylene glycol in PETG materials as an alternative to the standard USP colorimetric method. The method is based on the derivatization of ethylene glycol with benzoyl chloride in a Schotten-Baumann reaction. We present a comprehensive method development and validation. The method allows the detection and quantification of leached and extracted ethylene glycol directly in biopharmaceuticals after years of storage in contact with PETG bottles. Results showed residual ethylene glycol in drug substances to a level of ≈  0.1-0.5 µg/mL exposed during 2-6 years of storage in PETG bottles and ≈ 0.2-0.9 µg/mL in biopharmaceuticals. Graphical abstract Biopharmaceuticals must be free or low concentration for leachables, FR-UHPLC-UV analysis is a precise and accurate analytical method for ethylene glycol measurement. This leachable is commonly present in products in direct contact with PETG plastic.

Common Hydraulic Fracturing Fluid Additives Alter the Structure and Function of Anaerobic Microbial Communities.

The development of unconventional oil and gas (UOG) resources results in the production of large volumes of wastewater containing a complex mixture of hydraulic fracturing chemical additives and components from the formation. The release of these wastewaters into the environment poses potential risks that are poorly understood. Microbial communities in stream sediments form the base of the food chain and may serve as sentinels for changes in stream health. Iron-reducing organisms have been shown to play a role in the biodegradation of a wide range of organic compounds, and so to evaluate their response to UOG wastewater, we enriched anaerobic microbial communities from sediments collected upstream (background) and downstream (impacted) of an UOG wastewater injection disposal facility in the presence of hydraulic fracturing fluid (HFF) additives: guar gum, ethylene glycol, and two biocides, 2,2-dibromo-3-nitrilopropionamide (DBNPA) and bronopol (C3H6BrNO4). Iron reduction was significantly inhibited early in the incubations with the addition of biocides, whereas amendment with guar gum and ethylene glycol stimulated iron reduction relative to levels in the unamended controls. Changes in the microbial community structure were observed across all treatments, indicating the potential for even small amounts of UOG wastewater components to influence natural microbial processes. The microbial community structure differed between enrichments with background and impacted sediments, suggesting that impacted sediments may have been preconditioned by exposure to wastewater. These experiments demonstrated the potential for biocides to significantly decrease iron reduction rates immediately following a spill and demonstrated how microbial communities previously exposed to UOG wastewater may be more resilient to additional spills.IMPORTANCE Organic components of UOG wastewater can alter microbial communities and biogeochemical processes, which could alter the rates of essential natural attenuation processes. These findings provide new insights into microbial responses following a release of UOG wastewaters and are critical for identifying strategies for the remediation and natural attenuation of impacted environments.

Comparison of Mannose, Ethylene Glycol, and Methoxy-Terminated Diluents on Specificity and Selectivity of Electrochemical Peptide-Based Sensors.

We report the synthesis and application of three new antifouling diluents for the fabrication of an E-PB HIV sensor. Among the three thiolated antifouling diluents used in this study, the methoxy-terminated diluent (C6-MEG) is the most effective in alleviating both nonspecific binding and adsorption of matrix contaminants onto the sensor surface, especially when compared to the mannose- (C6-MAN) and ethylene-glycol-terminated (C6-EG) diluents. The sensor fabricated with C6-MEG has a specificity factor (∼13.5) substantially higher than the sensor passivated with only 6-mercapto-1-hexanol (∼1.5). It is functional even when employed directly in 25% serum, an achievement that has not been observed with this class of E-PB sensors. More importantly, incorporation of these antifouling diluents has negligible impact on other important sensor properties such as sensitivity and binding kinetics. This sensor passivation strategy is versatile and can potentially be used with other E-PB sensors, as well as surface-based sensors that utilize thiol-gold self-assembled monolayer chemistry.

Ethylene glycol emissions from on-road vehicles.

Ethylene glycol (HOCH2CH2OH), used as engine coolant for most on-road vehicles, is an intermediate volatility organic compound (IVOC) with a high Henry's law coefficient. We present measurements of ethylene glycol (EG) vapor in the Caldecott Tunnel near San Francisco, using a proton transfer reaction mass spectrometer (PTR-MS). Ethylene glycol was detected at mass-to-charge ratio 45, usually interpreted as solely coming from acetaldehyde. EG concentrations in bore 1 of the Caldecott Tunnel, which has a 4% uphill grade, were characterized by infrequent (approximately once per day) events with concentrations exceeding 10 times the average concentration, likely from vehicles with malfunctioning engine coolant systems. Limited measurements in tunnels near Houston and Boston are not conclusive regarding the presence of EG in sampled air. Previous PTR-MS measurements in urban areas may have overestimated acetaldehyde concentrations at times due to this interference by ethylene glycol. Estimates of EG emission rates from the Caldecott Tunnel data are unrealistically high, suggesting that the Caldecott data are not representative of emissions on a national or global scale. EG emissions are potentially important because they can lead to the formation of secondary organic aerosol following oxidation in the atmospheric aqueous phase.

[Determination of ethylene glycol in workplace air by capillary column gas chromatography].

OBJECTIVE: To establish the method of capillary column gas chromatography for determination of ethylene glycol in workplace air. METHODS: Ethylene glycol in workplace air was collected with silicone tube, desorbed with methanol, separated with FFAP (nitroterephthalic acid-modified polyethylene glycol)capillary column, and measured with flame ionization detector. RESULTS: The detection limit of ethylene glycol was 0.41 mg/L, the lower limit of quantification was 1.4 mg/L, the range of measurement was 1.4~163.9 mg/L, and the minimum detectable concentration was 0.3 mg/m3 (1.5 L of air was collected as the sample). This method had a good repeatability, the relative standard deviation was 1.4%~5.2%, the average desorption efficiency was 94.4%~101.7%, and the sampling efficiency was 99.2%~100%. The penetrating capacity of 200 mg silicone was higher than 6.9 mg, and the samples could be preserved for 14 days at room temperature. CONCLUSION: The method has a low detection limit, high accuracy, and good precision, which is feasible for determination of ethylene glycol in workplace air.

Use of ethylene glycol to evaluate gradient performance in gradient-intensive diffusion MR sequences.

Imaging a phantom of known dimensions is a widely used and simple method for calibrating MRI gradient strength. However, full-range characterization of gradient response is not achievable using this approach. Measurement of the apparent diffusion coefficient of a liquid with known diffusivity allows for calibration of gradient amplitudes across a wider dynamic range. An important caveat is that the temperature dependence of the liquid's diffusion characteristics must be known, and the temperature of the calibration phantom must be recorded. In this report, we demonstrate that the diffusion coefficient of ethylene glycol is well described by Arrhenius-type behavior across the typical range of ambient MRI magnet temperatures. Because of ethylene glycol's utility as an NMR chemical-shift thermometer, the same (1)H MR spectroscopy measurements that are used for gradient calibration also simultaneously "report" the sample temperature. The high viscosity of ethylene glycol makes it well-suited for assessing gradient performance in demanding diffusion-weighted imaging and spectroscopy sequences.

[Ethylene glycol poisoning--the significance of analytical diagnosis based on reports from Wielkopolska]. / Znaczenie diagnostyczne oznaczenia glikolu etylenowego w ostrych zatruciach--analiza przypadków z terenu województwa wielkopolskiego.

Ethylene glycol (EG) is a multidirectional, dihydric alcohol, which is widely used in food, chemical and automotive industries. EG is a compound of similar toxicity to ethanol (EA). The EG biotransformation undergoes, mainly to glycolaldehyde and acids: glycolic, glyoxylic and oxalic acid, such metabolites, which exhibit strong narcotic effect on the central nervous system, causing profound metabolic acidosis and lead to severe nephropathy. Due to the wide availability of products containing ethylene glycol and its potential toxicity, in the case of the alcohol poisoning, the significant role in the diagnosis play: medical interview, observation of characteristic clinical symptoms, basic laboratory tests and detection of ethylene glycol in the biological material that confirm EG poisoning.

Bioplastics from feather quill.

Poultry feather quills have been extruded in a twin screw extruder with sodium sulfite treatment as a reducing agent. The effect of four different plasticizers (ethylene glycol, propylene glycol, glycerol, and diethyl tartrate) on the thermoplastic properties was then investigated. Conformational changes and plasticizer-protein interactions in the extruded resins were assessed by Fourier transform infrared spectroscopy (FTIR), while viscoelastic behavior of the quill keratin plasticized with different plasticizers was investigated by dynamic mechanical analysis (DMA). Differential scanning calorimetry (DSC) was used to determine the effect of different plasticizers on protein denaturation. Thermal degradation patterns of the extrudates were studied by thermogravimetric analysis (TGA). The effect of plasticizers on the mechanical properties of resins was also assessed by tensile strength measurements. Results indicated that ethylene glycol was able to interact more effectively with quill keratin at the molecular level, exhibiting only one sharp glass transition, better mechanical properties, and higher transparency compared to other plasticized resins. The two phases found in glycerol plasticized material were attributed to glycerol-rich and protein-rich zones. Propylene glycol and diethyl tartrate exhibited lower H-bonding interactions and showed wide transition regions in DMA profiles during heating, suggesting weak and heterogeneous interactions between quill keratin and these plasticizers.

Purification of compounds from Lignum Dalbergia Odorifera using two-dimensional preparative chromatography with Click oligo (ethylene glycol) and C18 column.

Purification of compounds from traditional Chinese medicines (TCMs) is an important task for understanding the chemical composition of TCMs. However, it is difficult to obtain compounds with high enough purity for identification by NMR due to the complexity of TCMs in chemical composition. In this study, a two-dimensional purification method based on a Click oligo (ethylene glycol) column and a C18 column was developed to realize an orthogonal separation in preparative level for purifying compounds efficiently. The first dimensional preparation was performed on a Click oligo (ethylene glycol) column to simplify the sample into the fractions with good separation repeatability. On the first dimension, 7.2 g sample was separated into 11 fractions with a recovery of 86% within 6 h. A C18 column was taken as the second dimension to realize the high-performance separation and rapid preparation from the fractions collected from the first dimension. Eight compounds in fraction 6 and 2 compounds in fraction 8 were isolated and identified after optimizing the separation and collection parameters. This method is a high-efficient and orthogonal preparation method to improve the separation of a complex sample and increase the purity of the compounds, which benefits from the application of novel materials in the preparation and purification.

Simultaneous quantification of ethylene glycol and diethylene glycol in beer by gas chromatography coupled to mass spectrometry.

An analytical method for the simultaneous determination of ethylene glycol and diethylene glycol in beer was developed and validated according to current legislation. This method includes the application of sample dilution with ethanol followed by quantification using gas chromatography coupled to mass spectrometry. All figures of merit were within the limits established by regulation. The recoveries of the analytes, expressed as mean recovery, were between 91.9% and 108.9%. Precision, in terms of repeatability and intermediate precision, was established (relative standard deviations were lower than or equal to 10%). The limits of detection (10.0 and 5.0 mg.L-1 for ethylene glycol and diethylene glycol, respectively) and quantification (15.0 mg.L-1 for ethylene glycol and diethylene glycol) obtained were appropriate. Finally, the present method was applied for determination of ethylene glycol and diethylene glycol in 701 beer samples (from 67 different brands and 128 different labels), proving to be reliable.

Contaminated soils (III): in vitro dermal absorption of ethylene glycol and nonylphenol in human skin.

Dermal absorption of contaminants from soils at federal contaminated sites in Canada was investigated using one hydrophile, (14)C-ethylene glycol (EG), and one lipophile, (14)C-nonylphenol (NP). In vitro dermal absorption of EG and NP was examined in dermatomed (0.4-0.5 mm) human skin using Bronaugh Teflon flow-through cells with Hanks HEPES buffered (pH 7.4) receiver solution with 4% bovine serum albumin (BSA). Tests were conducted under occlusive conditions with and without a commercial gardening soil spiked with EG or NP applied to skin at a soil load of 5 mg/cm(2). With percent absorption in skin depot included, a total of 9.9 + or - 6.28% (n = 6) and 34.8 + or - 8.47% (n = 6) absorption of EG with and without soil, respectively, and 20.6 + or - 5.56% (n = 7) and 41.1 + or - 6.46% (n = 7) of NP, with and without soil, respectively, were obtained. For tests without soil a reverse pattern was observed with significantly lower percent absorption into the receiver than depot with the lipophile NP, but significantly higher percent absorption in receiver versus depot for the hydrophile EG. This pattern was different in tests with soil, and caution needs to be exercised when extrapolating data from in vitro tests conducted without soil in human health risk assessments at contaminated sites.

Dermal penetration of ethylene glycol through human skin in vitro.

This study was conducted to determine the in vitro dermal absorption of ethylene glycol (EG) through dermatomed human abdominal skin (containing epidermis and dermis), obtained from cadavers within 24 hours of death and kept frozen until processed. Three formulations of EG (neat, 50%, and 10% aqueous solutions) were applied in triplicate to skin samples from 6 donors, and placed in Teflon Bronaugh flow-through diffusion cells. Barrier integrity of each sample was evaluated with (3)H-H(2)O prior to applying EG and only data from samples passing the test were used. A physiological receptor fluid was pumped beneath the skin samples and collected in a fraction collector at predetermined time points through 24 hours. Possible volatilized EG was trapped in a charcoal basket located above each skin sample. Each skin sample was treated with an infinite dose of 500 microL of EG formulation/cm(2). At the end of 24 hours, volatilized EG trapped in the headspace was collected, the unabsorbed dose was removed from the skin and the skin was rinsed, tape stripped, and solubilized along with a rinse of the flow-through cells, and total radioactivity was determined. Only a small fraction (

Simplified assay of diethylene glycol and ethylene glycol in various raw materials by capillary gas chromatography.

The FDA has recently taken steps to reduce risks due to raw materials affected by economically motivated adulteration (EMA). One area of great interest is diethylene glycol (DEG) or ethylene glycol (EG) adulteration of glycerin, propylene glycol, and solutions of sorbitol, for which the USP monographs have recently been revised (1). Such adulterations have occurred many times and in many countries, including a tragic episode between November 2008 and January 2009 in which 84 children in Nigeria died after ingesting teething syrup contaminated with DEG (9,10). To eliminate this problem, the FDA has required manufacturers of finished products to assay and confirm that incoming glycerin, propylene glycol, and sorbitol solutions meet the USP limits, and the FDA/USP has incorporated such testing into the identity requirements of its updated monographs.Unfortunately, even though USP test procedures detail a simultaneous DEG and EG assay for these materials, different standard solutions are specified depending upon whether the incoming sample is glycerin, propylene glycol, or a sorbitol solution; in addition, a certain gas chromatography (GC) capillary phase is detailed for sorbitol solutions, while the assays for glycerin and propylene glycol use a different capillary phase, requiring column changeovers, separate GC systems, or front/rear column configuration. In addition, NF monographs for polyethylene glycols (PEG) and polyethylene glycol monomethyl ethers (MPEG) used in pharmaceutical products also require DEG and EG testing (detailing their own specific tests); three separate test procedures for these types of raw materials (the larger PEG-type polymers are assayed differently than their smaller counterparts), making assay at QC unwieldy.This paper describes a single, simple test procedure that is applicable to the simultaneous assay of DEG and EG in all types of the described raw materials, using one standard solution. The assay procedure involves straightforward isolation, trimethylsilylation, and simultaneous capillary gas chromatographic quantitation using capillary GC with flame ionization detection. Although the USP-NF limits are 0.10% DEG and 0.10% EG (and 0.25% total DEG plus EG for the PEG and MPEG products), in reality any EMA would be at levels significantly higher than that, as low-level illegal EMA would not be economically advantageous. The scope of this project was not to fully validate this technique for inclusion in USP-NF, but just to demonstrate its applicability for those wishing to utilize it or take it further.

A Single-Column Gas Chromatography Method for Quantifying Toxic Alcohols.

BACKGROUND: Rapid identification and quantification of toxic alcohols and ethylene glycol is imperative for appropriate treatment. Clinical laboratories frequently rely on direct injection gas chromatography (GC) methods, but these methods require inlet maintenance and multiple GC systems. To overcome these challenges, we developed a single-column headspace GC method for both toxic alcohols and glycols that streamlines patient sample analysis for toxic alcohol ingestion. METHODS: Optimal parameters for nonderivatized (volatile) and derivatized (glycol) plasma samples were determined using a 7890 A headspace sampler, an Agilent 7697 A GC system, a DB-200 column, and a flame ionization detector. Limit of Quantification (LoQ), linearity, imprecision, carry-over, method comparison, and interference studies were performed using quality control materials and prepared plasma samples. RESULTS: Our volatile method is linear to 3000 mg/L (ethanol) with LoQ concentrations below 20 mg/L (ethanol). The glycol method is linear to 2000 mg/L (ethylene glycol) with LoQ concentrations below 40 mg/L (ethylene glycol). Total assay impression ranged from 1.7% for ethanol to 13.3% for propylene glycol. Both methods were free of sample carryover and compared favorably with a similar clinical method at an outside laboratory. Propionic acid, an accumulating metabolite in methylmalonic acidemia that interferes with ethylene glycol identification by a different method, did not interfere with the ethylene glycol method reported here. CONCLUSIONS: Our single-column headspace GC method provides reliable, robust, and rapid identification and quantification of commonly encountered toxic alcohols. Clinical laboratories relying on direct injection Gas Chromatography (GC) for toxic alcohol analysis face challenges including frequent inlet maintenance, sample carryover, or the need for separate GC systems for volatile and glycol analysis. We summarize our development and optimization of two headspace GC methods for nonderivatized (volatile) and derivatized (glycol) plasma samples that use a single DB-200 analytical column. These methods are comparable to other GC methods, not prone to sample carryover, eliminate the need for multiple GC systems or columns, and are readily applicable to other laboratories that provide toxic alcohol analysis.

A sensitive estimation of residual ethylene glycol in ethylene oxide sterilized medical devices by HPLC with electrospray ionization mass spectrometric detection.

A novel analytical methodology for the estimation of residual ethylene glycol (EG) in ethylene oxide sterilized polymer is reported. The method involves the monitoring of ammonium adduct of EG ions in the presence of 10 mM ammonium acetate buffer and methanol using electrospray ionization liquid chromatography and mass spectrometry (LC-ESI-MS). The method enables the detection and quantification of EG without prior derivatization up to a level of 0.06 microg/ml. The potentiality of the method is demonstrated by estimating EG in ethylene oxide (EtO) sterilized polyethylene terephthalate fabric used in heart valve sewing ring. The method is simple, rapid and can routinely be used for the quantification of residual EG in EtO sterilized medical devices.

A fatal case involving extremely high levels of ethylene glycol without elevation of its metabolites or crystalluria.

A unique case of an intentional overdose of ethylene glycol resulting in a fatality is described. The decedent had a very high concentration of ethylene glycol without elevated concentrations of its metabolites or crystalluria. The ethylene glycol concentrations in blood, urine, and vitreous fluid were 2340, 2261, and 1028 mg/dL, respectively. Osmolality of blood and vitreous fluid was also very high at 1426 and 534 mOsm/kg, respectively. No crystals were found in the urine. Furthermore, on the urine organic acids profile the ethylene glycol metabolites oxalic, glycolic, and glyoxylic acids were within the reference ranges. In addition to ethylene glycol, the decedent had an elevated level of mirtazapine, an antidepressant, and a low level of bupropion. It was estimated that the subject consumed 1034 g of ethylene glycol. To our knowledge, this is the first case of death from severe ethylene glycol poisoning in the absence of ethylene glycol metabolites or crystalluria.

Hydrophilic interaction chromatography in nonaqueous elution mode for separation of hydrophilic analytes on silica-based packings with noncharged polar bondings.

Chromatographic effects of dedicated stationary and mobile phase variations in hydrophilic interaction chromatography (HILIC) were investigated using a set of nucleobases, nucleosides and deoxynucleosides as polar test solutes. Retention and selectivity profiles were comparatively mapped on four in-house developed silica materials modified with short alkyl chains (C4, C5) which carry hydroxyl functionalities (including diol motifs) as well as embedded sulphide or sulphoxide groups. These data were complemented by results obtained with two commercially available diol-type phases and a bare silica column. Besides elucidation of packing-related aspects this work concentrated specifically on extending aqueous HILIC (AQ-HILIC) to nonaqueous polar-organic elution conditions herein termed NA-HILIC. The exchange of the polar modifier water by various alcohols in ACN-rich mobile phases containing 5 mM ammonium acetate decreased the eluotropic strength of the resulting eluents. The gain in retention largely followed the order ethanol (EtOH)>methanol (MeOH)>1,2-ethanediol (Et(OH)2) and was accompanied by distinct effects on chromatographic selectivity. For example, on the most polar home-made packing the purine nucleoside selectivity guanosine/adenosine increased from 2.25 in the AQ-HILIC (kguanosine=8.3) to 7.33 (kguanosine=59) in the NA-HILIC mode when EtOH was employed as NA modifier while this value was 5.84 and 2.93 with MeOH and Et(OH)2, respectively (eluent: 5 mM ammonium acetate in ACN/modifier 90:10 v/v). Besides the type of protic modifier its percentage as well the retention and selectivity effects upon varying the ammonium acetate concentration and column temperature, respectively, were also investigated. Notable inter-column differences were found for all of these elution parameters. A mixed-mode retention model composed of partitioning and adsorption is proposed for both AQ- and NA-HILIC retention processes. The potential of (i) the implementation of novel polar bondings (such as ones containing sulphoxide functionalities) and (ii) the comprehensive exploitation of elution variables (type of protic modifiers, salt, etc.) for providing new selectivity increments to the separation of polar analytes in HILIC is emphasised.

Referenced MR thermometry using three-echo phase-based fat water separation method.

A three-point image reconstruction method for internally referenced MR thermometry was developed. The technique exploits the fact that temperature-induced changes in the water resonance frequency are small relative to the chemical shift difference between water and fat signals. This property enabled the use of small angle approximations to derive an analytic phase-based fat-water separation method for MR thermometry. Ethylene glycol and cream cool-down experiments were performed to validate measurement technique. Over a cool-down temperature range of 20 °C, maximum deviation between probe and MR measurement (averaged over 1.3 cm3 region surrounding probe) was 0.6 °C and 1.1 °C for ethylene glycol and cream samples, respectively.

Curcumin alleviated oxidation stress injury by mediating osteopontin in nephrolithiasis rats

Purpose: To explore the role and mechanism of curcumin (Cur) in reducing oxidative stress damage in rats with nephrolithiasis induced by ethylene glycol (EG). Methods: Thirty male rats were divided into normal control, model, positive (10% potassium citrate), Cur-10 (10 mg/kg curcumin) and Cur-20 (20 mg/kg curcumin) groups. Results: The results of kidney tissue section stained by hematoxylin-eosin and von Kossa showed that curcumin treatment can inhibit the formation of kidney stones. The biochemical test results showed that the urea (Ur), creatinine (Cr), uric acid (UA), inorganic phosphorus and Ca2+ concentrations in urine decreased after being treated with curcumin. There were significant differences between different doses of curcumin (P < 0.05). Compared with the Cur-10 group, Cur-20 had a more significant inhibitory effect on malondialdehyde (MDA) (P < 0.05). In addition, reverse transcription polymerase chain reaction (PCR) detection and immunohistochemical results indicated that the osteopontin (OPN) in the kidney was significantly reduced after curcumin treatment. Conclusion: Curcumin could reduce the oxidative stress damage caused by EG-induced kidney stones.