2-aminothiazoline-4-carboxylic acid (ATCA) is a minor metabolite of cyanide and is suggested to be a promising biomarker for cyanide exposure due to its specificity to cyanide metabolism and its excellent short-and long-term stability during storage. In this study, magnetic carbon nanotubes, including magnetic multi-walled carbon nanotubes (Mag-MWCNT) and magnetic single-walled carbon nanotubes (Mag-SWCNT) were synthesized as a novel sorbent for dispersive micro solid phase extraction (d-μSPE) to extract ATCA from biological matrices. ATCA spiked deionized water samples with the addition of the isotopic internal standard (ATCA -13 C, 15 N) were subjected to Mag-CNT/d-μSPE to confirm extraction efficiency of this new technique. The extracted ATCA was derivatized and quantitated using gas chromatography/mass spectrometry (GC/MS) analysis. The extraction parameters were optimized and a detection limits of 15 and 25 ng/mL were obtained for synthetic urine and bovine blood respectively with a linear dynamic range of 30 -1000 ng/mL. The optimized Mag-CNT/d-μSPE method facilitated efficient extraction of ATCA using 2 mg of Mag-MWCNT with a 10-minute extraction time. The current assay was also found to be effective for the extraction of ATCA with average recoveries of 97.7 ± 4.0% (n=9) and 96.5 ± 12.1% (n=9) from synthetic urine and bovine blood respectively. The approach of using Mag-CNT to facilitate d-μSPE offered a novel alternative to extract ATCA from complex biological matrices.

This study reports the long-term storage stability of a formulation of the cyanide (CN) antidote dimethyl trisulfide (DMTS). The F3-formulated DMTS was stored in glass ampules at 4, 22, and 37 °C. Over a period of one year, nine ampules ( n = 3 at each temperature) were analyzed by high-performance liquid chromatography (HPLC)–UV/vis at daily time intervals in the first week, weekly time intervals in the first month, and monthly thereafter for a period of one year to determine the DMTS content. No measurable loss of DMTS was found at 4 and 22 °C, and good stability was noted up to five months for samples stored at 37 °C. At 37 °C, a 10% (M/M) decrease of DMTS was discovered at the sixth month and only 30% (M/M) of DMTS remained by the end of the study; discoloration of the formulation and the growth of new peaks in the HPLC chromatogram were also observed. To identify the unknown peaks at 37 °C, controlled oxidation studies were performed on DMTS using two strong oxidizing agents: meta -chloroperoxybenzoic acid ( m CPBA) and hydrogen peroxide (H 2 O 2 ). Dimethyl tetrasulfide and dimethyl pentasulfide were observed as products using both of the oxidizing agents. Dimethyl disulfide was also observed as a product of degradation, which was further oxidized to S -methyl methanethiosulfonate only when m CPBA was used. HPLC–UV/vis and gas chromatography–mass spectrometry/solid phase microextraction analysis revealed good agreement between the degradation products of the stability study at 37 °C and those of disproportionation reactions. Furthermore, at 4 and 22 °C, chromatograms were remarkably stable over the one-year study period, indicating that the F3-formulated DMTS shows excellent long-term storage stability at T ≤ 22 °C.

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Traditional production processes are based on a reduction of materials until a product is created. This is usually accomplished with computerized numerical control (CNC) machinery and is often called subtractive manufacturing and will result in waste accumulation. Three-dimensional (3D) printing technologies, also called additive manufacturing, have

Although kombucha is a popular fermented beverage, the presence of alcohol markers has not been well studied despite being potential indicators of unintentional impairment. Ethyl glucuronide (EtG) and ethyl sulfate (EtS) were measured in oral fluid and urine collected after consumption of regular or hard kombucha. Participants drank within 20 min and provided all urine voids for 12 h, the first urine voids on days 2 and 3, and oral fluid specimens at fixed time points for 48 h. Screening employed liquid chromatography–tandem mass spectrometry (LC–MS-MS; EtS, 25 ng/mL cutoff [oral]; 100 ng/mL cutoff [urine]; EtG, 500 ng/mL cutoff [urine] and immunoassay (IA; EtG, 500 ng/mL cutoff[urine]). After consuming regular kombucha (n = 12 participants), EtS was not detected in oral fluid but both markers were detected by LC–MS-MS in urine specimens within the first 5 voids from 83% of participants with median (range) concentrations of 240 (100–3,700) ng/mL for EtS and 830 (530–2,200) ng/mL for EtG. Neither marker was positive by IA nor LC–MS-MS after day 1. After consuming hard kombucha (n = 7 participants), 2 (2.8%) of the 70 collected oral fluid specimens tested positive for EtS 3 h after consumption; however, 21 (30%) had EtS levels above the limit of detection (LOD, 10 ng/mL) after 0.5–8 h. Both markers were detected in urine specimens from all participants with median (range) concentrations of 3,381 (559–70,250) ng/mL for EtS and 763 (104–12,864) ng/mL For EtG. Urine specimens were negative for EtG and EtS by the end of the 48-hour study.