Cartridge Purification Research Articles

18F]Fluoromisonidazole synthesis method: development and optimization by cartridge purification

Abstract [18F]Fluoromisonidazole ([18F]FMISO) as nitroimidazole derivative with 18F radioisotope is a widely known and studied hypoxia marker for PET imaging. A number of automated synthesis modules and purification strategies for production of [18F]FMISO have been described in recent years. The goal of this work was to develop [18F]FMISO synthesis process with Synthera module with solid phase extraction (SPE) Sep-Pak purification cartridges. To adjust the reaction conditions we synthesized [18F]FMISO under different reaction conditions and using various reversed-phase (RP) purification cartridges (HLB light, HLB plus, tC18, C18 environmental, Chromafix PS-RP). The synthesis was performed by nucleophilic substitution of commercial 1-(2′-nitro-1′-imidazolyl)-2-O-tetrahydropyranyl-3-O-toluenesulfonylpropanediol precursor and subsequent acidic hydrolysis. Further, the product mixture was purified by passing through the SPE cartridge. The produced [18F]FMISO was retained on the cartridge, while the impurities passed through the cartridge into a waste. The retained [18F]FMISO was then eluted with small amounts of ethanol in water and eluates were collected in the final product vial. The product sample was subjected to quality control tests, while for waste sample chemical and radiochemical tests were performed. We have developed an efficient synthesis method of [18F]FMISO with cartridge purification with good radiochemical yield (RCY) and high chemical and radiochemical purity in accordance with the Ph. Eur. Monograph for Fluoromisonidazole (18F) injection.

GC-MS/MS Method for Determination of Polycyclic Aromatic Hydrocarbons in Herbal Medicines.

Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic organic contaminants that have a highly carcinogenic and mutagenic nature. This study aimed to develop and validate a sensitive analytical method to determine 8 PAHs in 51 herbal medicines (HMs) using gas chromatography (GC)-tandem mass spectrometry (MS/MS). Liquid--liquid extraction and florisil SPE cartridge purification were basically adopted for pretreatment. For the samples containing essential oil, starch grain, etc., N,N-dimethyl formamide/water mixture (9:1, v/v) was added in the extraction step. The multiple reaction monitoring (MRM) conditions were newly obtained by the infusion of reference solutions of the targeted compounds at a concentration of 100 ng/mL into the GC-MS/MS system used in this study. The 51 items were classified according to whether or not they contained essential oil. Eight PAHs were not detected in 39 (8.3%) of the 459 samples monitored. The total content of 8 PAHs ranged from 0.45 μg/kg in Anemarrhenae Rhizoma to 270.94 μg/kg in Zingiberis Rhizoma. The average content of those ranged from 0.9 μg/kg in Araliae Continentalis Radix to 110.8 μg/kg in Coptidis Rhizoma Preparata cum Vinum. The results of this study prove that the proposed method is useful for determining 8 PAHs in HMs.

Simultaneous determination of nine estrogens in bullfrogs using filtered solid phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry

建立了基于通过型固相萃取小柱净化的超高效液相色谱-三重四极杆质谱联用(UPLC-MS/MS)同时快速准确测定牛蛙中9种雌激素(雌三醇(E3)、17β-雌二醇(β-E)、17α-雌二醇(α-E)、17α-炔二雌醇(EE2)、雌酮(EI)、己烯雌酚(DES)、己二烯雌酚(DE)、己烷雌酚(HEX)、醋酸双烯雌酚(DD))残留的检测方法。样品经乙腈提取,经PRiME HLB固相萃取柱净化,Waters Acquity UPLC BEH C18柱(100 mm×2.1 mm, 1.7 μm)分离,以0.5 mmol/L氟化铵水溶液-乙腈体系为流动相梯度洗脱,流速为0.3 mL/min,采用电喷雾正负离子切换模式(ESI+/ESI-)和多反应监测(MRM)扫描方式检测,基质匹配外标法定量分析。该研究优化了液相色谱条件,相比于乙酸铵水溶液-乙腈体系和氨水溶液-乙腈体系,0.5 mmol/L氟化铵水溶液-乙腈体系作为流动相时9种雌激素普遍具有更佳的灵敏度。相比于甲醇和乙酸乙酯,乙腈作为提取溶剂时9种雌激素的提取率提高15%~40%。考察了HLB、C18、Silica、PRiME HLB共4种不同类型的固相萃取小柱的基质净化效应,结果表明,PRiME HLB柱具有更好的基质净化能力。经PRiME HLB净化后,所有化合物的回收率均在70%~125%之间。DD的回收率从47%提高到74%, DES的回收率从180%降低到123%,有效减弱了基质效应。在最佳的实验条件下,E3、β-E、α-E、EI、DE、HEX、DD的线性范围为0.5~100.0 μg/L, EE2和DES的线性范围为1.0~100.0 μg/L, 9种雌激素在各自的线性范围内均有良好的线性关系,相关系数为0.9953~0.9994,方法检出限为0.17~0.33 μg/kg,方法定量限为0.5~1.0 μg/kg,在2.0、10.0、80.0 μg/kg 3个加标水平下,9种雌激素的加标回收率为65.1%~128.2%,相对标准偏差为1.9%~17.6%。该方法操作简便、快速、灵敏,重复性好,可用于大批量样品的同时快速准确检测。

Simultaneous determination of triazine herbicides and their metabolites in shellfish by HPLC-MS/MS combined with Q/E-Orbitrap HRMS.

Triazine herbicides are used extensively in agriculture and aquaculture worldwide because of their broad effectiveness in weed control. However, after they are discharged into the sea, they seriously contaminate aquatic ecosystems and threaten aquatic organisms, especially shellfish. Currently, there are no established methods for the detection and confirmation of triazine herbicides and their metabolites in biological matrixes. Hence, the food safety of aquatic products cannot be accurately evaluated, which creates a technical barrier against international aquatic product trade. In this study, for the first time, a method was developed for the analysis and confirmation of seven triazine herbicides and 13 metabolites in shellfish, based on alkaline acetonitrile extraction and neutral Al2O3 cartridge purification coupled with internal standard calibration. Specifically, quantitative and qualitative analysis was conducted using high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MS), and accurate identification was carried out by quadrupole orbitrap high-resolution mass spectrometry (Q/E Orbitrap HRMS). The results showed that target analytes demonstrated good linearity within the corresponding range (R2 > 0.995). The limit of detection and limit of quantitation of the proposed method were 0.1 and 0.3 μg/kg, respectively. The average recoveries of analytes were between 70.0% and 120% when spiked at three levels with blank oyster (Crassostrea gigas) as the matrix, and the relative standard deviations (RSDs) were all less than 12% (n=6). The proposed method was successfully applied for the detection of triazine herbicide residues in oyster samples during actual breeding, and the presence of DIP, HP, DEHA, and other metabolites in positive samples was confirmed by Q/E Orbitrap HRMS. This method exhibits high accuracy, high sensitivity, and good reproducibility. It has promising application prospects in the field of hazard analysis and the positive identification of aquatic products.

Development of a PRiME cartridge purification method for rapid determination of malachite green and leucomalachite green in Chinese softshell turtle.

A high-throughput PRiME (process, robustness, improvements, matrix effects, ease of use) sample purification procedure was developed to simplify the multiple steps of traditional SPE in extracting the malachite green and leucomalachite green in Chinese softshell turtle (Pelodiscus sinensis). The sample loading volume, extracting solvent type, and pH value of the employed PRiME hydrophilic-lipophilic balance cartridge for sample purification were optimized to be 3 mL, acetonitrile, and pH 5, respectively. In comparison with traditional SPE, the PRiME process is cost-effective, solvent-saving, and simple to operate, which only consists of a passing through step without traditional sorbent conditioning and impurity washing. Afterward, eluate was analyzed by ultra-performance liquid chromatography-tandem mass spectrometry, and the proposed method was validated for linearity (R2 > 0.9992), intraday precision (2.44-3.22%), interday precision (3.28-6.58%), sensitivity (LOD ≤ 0.18 μg/kg and, LOQ ≤ 0.60 μg/kg), and recovery (88.7-94.1%, RSD < 6.79%). The results indicated that the PRiME technique can simplify the sample preparation procedure by avoiding the tedious steps, such as conditioning, washing, etc. It would be of significant interest for environmental and food safety applications in the market of Chinese softshell turtle and related products.

A simple and efficient automated cGMP-compliant radiosynthesis of [11 C]metomidate using solid phase extraction cartridge purification.

[11 C]metomidate ([11 C]MTO) is a radiotracer widely used to detect disorders of adrenocortical origin by positron emission tomography (PET) imaging. [11 C]MTO PET/computed tomography (PET/CT) is considered a sensitive and specific noninvasive alternative to adrenal vein sampling (AVS) in the management of primary hyperaldosteronism (PHA). Herein, we report a reliable automated procedure for the routine manufacturing of [11 C]MTO in current good manufacturing practice (cGMP) conditions on the commercial Synthra MeIPlus Loop Vessel synthesizer. The method is based on a combination of the captive-solvent 11 C-methylation of the carboxylate salt 1b of the MTO precursor 1a followed by solid phase extraction (SPE) cartridge purification methodology, which substitutes HPLC purification of the crude reaction mixture. Starting from 45GBq [11 C]CO2 at the end of bombardment (EOB), 3GBq of pure [11 C]MTO was produced in 18minutes with 12% decay corrected radiochemical yield (RCY) at the end of synthesis (EOS) and with the modest molar activity of 13GBq/μmol at the time of application. Each dose produced met all established quality control (QC) criteria. The method can easily be implemented into other commercial automated radiosynthesizers for manufacturing carbon-11 labeled radiotracers.

Efficient cartridge purification for producing high molar activity [18F]fluoro-glycoconjugates via oxime formation

Introduction18F-fluoroglycosylation via oxime formation is a chemoselective and mild radiolabeling method for sensitive molecules. Glycosylation can also improve the bioavailability, in vivo kinetics, and stability of the compound in blood, as well as accelerate clearance of biomolecules. A typical synthesis procedure for 18F-fluoroglycosylation with [18F]FDG (2-deoxy-2-[18F]fluoro-d-glucose) and [18F]FDR (5-deoxy-5-[18F]fluoro-d-ribose) involves two HPLC (high performance liquid chromatography) purifications: one after 18F-fluorination of the carbohydrate to remove its labeling precursor, and a second one after the oxime formation step to remove the aminooxy precursor. The two HPLC purifications can be time consuming and complicate the adaptation of the synthetic strategy in nuclear medicine applications and automated synthesis. We have developed a procedure in which SPE (solid phase extraction) and resin purification methods replace both of the needed HPLC purification steps. MethodsWe used [18F]FDR and [18F]FDG as prosthetic groups to radiolabel two aminooxy-modified model molecules, a tetrazine and a PSMA (prostate specific membrane antigen) inhibitor. After fluorination, the excess carbohydrate precursor was removed by derivatizing it with 4,4′-dimethoxytrityl chloride (DMT-Cl). The DMT moiety increases the hydrophobicity of the unreacted precursor making the separation from the fluorinated precursor possible with simple C18 Sep-Pak cartridge. For removal of the aminooxy precursor, we used a commercially available aldehyde resin (AminoLink, Thermo Fisher Scientific). C18 Sep-Pak SPE cartridge was used to separate [18F]FDR and [18F]FDG from the 18F-fluoroglycoconjugate end product. Results[18F]FDR and [18F]FDG were efficiently purified from their precursors, free fluorine-18, and other impurities. The aldehyde resin quantitatively removed the unreacted aminooxy precursors after the oxime formation. The fluorine-18 labeled oxime end products were obtained with high radiochemical purity (>99%) and molar activity (>600 GBq μmol−1). ConclusionsWe have developed an efficient cartridge purification method for producing high molar activity 18F-glycoconjugates synthesized via oxime formation.

Streamlined chemoenzymatic total synthesis of prioritized ganglioside cancer antigens.

A highly efficient streamlined chemoenzymatic strategy for total synthesis of four prioritized ganglioside cancer antigens GD2, GD3, fucosyl GM1, and GM3 from commercially available lactose and phytosphingosine is demonstrated. Lactosyl sphingosine (LacβSph) was chemically synthesized (on a 13 g scale), subjected to sequential one-pot multienzyme (OPME) glycosylation reactions with facile C18-cartridge purification, followed by improved acylation conditions to form target gangliosides, including fucosyl GM1 which has never been synthesized before.

Acetonitrile extraction coupled with UHPLC-MS/MS for the accurate quantification of 17 heterocyclic aromatic amines in meat products.

This study proposed a simple and accurate acetonitrile extraction pretreatment method coupled with ultrahigh-performance liquid chromatography with tandem mass spectrometry for the simultaneous determination of 17 heterocyclic aromatic amines (HAAs) in meat products. With this new method, all 17 HAAs, including 11 polar and 6 nonpolarHAAs, were simultaneously extracted by acetonitrile and purified by one-step Oasis MCX cartridge purification. Compared with two different improved reference methods, the acetonitrile method could obtain higher recoveries (in the range of 42.5% to 99.0%) and better repeatability (lower than 12.2%). The limits of quantification were calculated between 0.028ngg-1and0.648ngg-1 with high correlation coefficients (r>0.9976) in wide linear ranges. The proposed acetonitrile method was successfully applied to the analysis of the HAAs levels in 10 commercial meat products with satisfactory recoveries.

Dual-Modality Imaging of Prostate Cancer with a Fluorescent and Radiogallium-Labeled Gastrin-Releasing Peptide Receptor Antagonist.

We designed and synthesized an IRDye 650 and DOTA-conjugated GRPr antagonist, HZ220 (DOTA-Lys(IRDye 650)-PEG4-[D-Phe6, Sta13]-BN(6-14)NH2), by reacting DOTA-Lys-PEG4-[D-Phe6, Sta13]-BN(6-14)NH2 (HZ219) with IRDye 650 N-hydroxysuccinimide (NHS) ester. Receptor-specific binding of gallium-labeled HZ220 was characterized in PC-3 prostate cancer cells (PC-3), and tumor uptake in mice was imaged with PET/CT and fluorescence imaging. Receptor binding affinity, in vivo tumor uptake, and biodistribution were compared with the GRPr antagonists HZ219, DOTA-PEG4-[D-Phe6, Sta13]-BN(6-14)NH2 (DOTA-AR), and DOTA-(4-amino-1-carboxymethyl-piperidine)-[D-Phe6, Sta13]-BN(6-14)NH2 (DOTA-RM2). After hydrophilic-lipophilic balance cartridge purification, 68Ga-HZ220 was obtained with a radiochemical yield of 56% ± 8% (non-decay-corrected), and the radiochemical purity was greater than 95%. Ga-HZ220 had a lower affinity for GRPr (inhibitory concentration of 50% [IC50], 21.4 ± 7.4 nM) than Ga-DOTA-AR (IC50, 0.48 ± 0.18 nM) or Ga-HZ219 (IC50, 0.69 ± 0.18 nM). Nevertheless, 68Ga-HZ220 had an in vivo tumor accumulation similar to 68Ga-DOTA-AR (4.63 ± 0.31 vs. 4.07 ± 0.29 percentage injected activity per mL [%IA/mL] at 1 h after injection) but lower than that of 68Ga-DOTA-RM2 (10.4 ± 0.4 %IA/mL). The tumor uptake of 68Ga-HZ220 was blocked significantly with an excessive amount of GRP antagonists. IVIS spectrum imaging also visualized PC-3 xenografts in vivo and ex vivo with a high-contrast ratio. Autoradiography and fluorescent-based microscopic imaging with 68Ga-HZ220 consistently colocated the expression of GRPr. 68Ga-HZ220 displayed a higher kidney uptake than both 68Ga-DOTA-AR and 68Ga-DOTA-RM2 (16.9 ± 6.5 vs. 4.48 ± 1.63 vs. 5.01 ± 2.29 %IA/mL). 68Ga-HZ220 is a promising bimodal ligand for noninvasive PET imaging and intraoperative optical imaging of GRPr-expressing malignancies. Bimodal nuclear/fluorescence imaging may not only improve cancer detection and guide surgical resections, but also improve our understanding of the uptake of GRPr ligands on the cellular level.

Investigation on the Profile of Phenolic Acids and Flavonoids with Antioxidant Capacity in Florida Highbush (Vaccinium corymbosum L.) and Rabbiteye (Vaccinium virgatum) Blueberries

It is well documented that blueberry phenolic compositions, such as phenolic acids and flavonoids differ based on species and cultivars. However, phenolic compositions in Florida blueberries have been little explored. Information on Florida blueberries are of interest as they are harvested earlier than other areas of the United States, which may result in compositional differences due to shorter daylight hours and cooler temperatures. Samples were harvested from University of Florida grower-cooperator farm near Gainesville, FL. After liquid-liquid extraction and C-18 SPE cartridge purification, concentrations of phenolic acids and flavonoids of twenty two blueberry cultivars (20 highbush and 2 rabbiteye) were measured using HPLC. Five phenolic acids (gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid and ferulic acid), two flavan-3-ols (catechin and epicatechin) and five flavonols (quercetin-3-galactoside or quercetin-3-glucoside, quercetin-3-arabinoside, myricetin, quercetin and kaempferol) were identified and quantified. Chlorogenic acid was the major component in highbush blueberries. Flavonoid and phenolic acid composition were profoundly different among Florida blueberries and these differences have not been previously reported. The first two components of PCA explained 95% of the variation totally; it showed clear differentiation of blueberry cultivars based on phenolic composition. The majority of the variation between the cultivars was due to variation in quercetin-3-galactoside or glucoside, quercetin-3-arabinoside and chlorogenic acid, which are most likely due to genetic and maturity differences. Complete-linkage clustering analysis displayed five significantly different (p<0.05) clusters of blueberries, which were in agreement with PCA results, although some small differences were noted. Furthermore, Florida blueberries can be differentiated based on phenolic composition between highbush and rabbiteye species and varieties. Low flavanol content in rabbiteye blueberries may be related to maturity as these compounds typically decrease as berries ripen. Although the concentrations for phenolic compositions were lower than found in other reports, Florida blueberries contained a greater range of phenolic compounds. This information is valuable for blueberry breeding programs and growers for development of higher phenolic composition cultivar.

Development of a Ga-68 labeled triptorelin analog for GnRH receptor imaging

Abstract Optimized total synthesis, radiolabeling and quality control of [68Ga]-DOTA-Hyd-TRP as an efficient and possible PET radiotracer for GnRH receptor imaging in various tumors is of great interest. DOTA-Hyd-TRP was synthesized using solid phase peptide synthesis followed by conjugation to DOTA using pSCN-Bn-DOTA. [68Ga]-DOTA-Hyd-TRP was prepared using generator-based [68Ga]GaCl3 and DOTA-Hyd-TRP under optimized conditions for time, temperature, ligand amount, gallium content and column cartridge purification followed by proper formulation. The biodistribution of the tracer in rats was studied using tissue counting up to 120 min. [68Ga]-DOTA-Hyd-TRP was prepared at optimized conditions in 5–7 min at 95 ℃ followed by separation using C18 cartridge (radiochemical purity ≈ 99 ± 0.88% ITLC, &gt; 99% HPLC, specific activity: 300 ± 15 MBq/nM). The biodistribution of the tracer demonstrated high kidney uptake of the tracer in 10–20 min as well as significant testicular uptake consistent with reported GnRH receptor mappings. Block test studies by triptorelin pretreatment of the animals prior to tracer administration demonstrated significant specific uptake in receptor rich organs including testes and stomach.

Urine 2DE proteome analysis in healthy condition and kidney disease.

Urine is a source of potential markers of disease. In the context of renal disease, urine is particularly important as it may directly reflect kidney injury. Current markers of renal dysfunction lack both optimal specificity and sensitivity, and improved technologies and approaches are needed. There is no clear consensus about the best sample pretreatment procedure for 2DE analysis of the urine proteome. Sample pretreatment conditions spots resolution and detection sensitivity, critically. As a first goal, we exhaustively compared eight different sample cleaning and protein purification methodologies for 2DE analysis of urine from healthy individuals. Oasis® HLB cartridges allowed the detection of the highest number of low molecular weight proteins; while PD10 desalting columns resulted in the highest number of detected spots in the high molecular weight area. Sample pretreatment strategies were also explored in the context of proteinuria, a clinical condition often associated to renal damage. Testing of urine samples from 13 patients with hypertension or kidney disease and different levels of proteinuria identified Oasis® HLB cartridge purification in combination with albumin depletion by ProteoPrep kit as the best option for urine proteome profiling from patients with proteinuric (> 30 mg/L albumin in urine) renal disease.

Fast and efficient microscale radiosynthesis of 3′-deoxy-3′-[18F]fluorothymidine

Microscale radiosynthesis on a miniaturized device has been reported as a promising tool for positron emission tomography. Here, we studied miscroscale-level radiosynthetic conditions by examining several microscale reactions that affect the radiochemical yield of 3′-deoxy-3′-[18F]fluorothymidine ([18F]FLT). [18F]FLT was prepared with 3-N-Boc-5′-O-dimethoxytrityl-3′-O-nosyl-thymidine using the cartridge purification method. [18F]FLT was prepared with a yield of 71%, and the product's purity was greater than 99%. Our results provide a new guideline for microscale [18F]FLT radiosynthesis.

Efficient microscale synthesis of [18F]-2-fluoro-2-deoxy-d-glucose

• [ 18 F]fluorination efficiency can be enhanced by flexible aliphatic tertiary alcohols. • [ 18 F]FDG was synthesized from mannose triflate on a micro-scale level with a higher radiochemical yield within shorter time. • Radiosynthesis of [ 18 F]FDG was influenced by ratio of tertiary alcohols and DMSO. • The concentrations of mannose triflate and bases influence on the microscale substitution reaction yield. Microscale radiosynthesis of [ 18 F]FDG using a miniaturized device has been reported as a promising tool for positron emission tomography. However, small scale [ 18 F]FDG radiosynthesis on micro fluidic devices need to be studied further to evaluate its usefulness. This paper analyzes several micro-scale reactions of [ 18 F]FDG with various reaction conditions to achieve a higher radiochemical yield of [ 18 F]FDG. Synthesis of [ 18 F]FDG was carried out using mannose triflate on a microchip, and the crude product was purified via cartridge purification. The reaction conditions were optimized by examining several factors including reaction solvents, bases and their concentrations, that influence microscale radio synthesis of [ 18 F]FDG. Based on the investigation of several variables and their effects on the radio-synthetic reaction, [ 18 F]FDG was successfully synthesized on a micro-scale level with a radiochemical yield of 71% and within shorter time frame than that of the traditional method. Moreover, purity of the product was greater than 99%. These results show that the new guideline provides a more efficient and effective method of microscale [ 18 F]FDG radiosynthesis.

Efficient Radiosynthesis of 3′-Deoxy-3′-18F-Fluorothymidine Using Electrowetting-on-Dielectric Digital Microfluidic Chip

Access to diverse PET tracers for preclinical and clinical research remains a major obstacle to research in cancer and other disease research. The prohibitive cost and limited availability of tracers could be alleviated by microfluidic radiosynthesis technologies combined with a high-yield microscale radiosynthetic method. In this report, we demonstrate the multistep synthesis of 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) with high yield on an electrowetting-on-dielectric (EWOD) microfluidic radiosynthesizer, previously developed in our group. We have identified and established several parameters that are most critical in the microscale radiosynthesis, such as the reaction time, reagent concentration, and molar ratios, to successfully synthesize (18)F-FLT in this compact platform. (18)F-FLT was synthesized from the 3-N-Boc-1-[5-O-(4,4'-dimethoxytrityl)-3-O-nosyl-2-deoxy-β-D-lyxofuranosyl] thymine precursor on the EWOD chip starting from the first solvent exchange and (18)F-fluoride ion activation step to the final deprotection step. The fluorination reaction was performed in a mixture of thexyl alcohol and dimethyl sulfoxide. The crude product after deprotection was collected from the chip and purified on a custom-made solid-phase extraction cartridge and subjected to quality control testing. The purified (18)F-FLT was suitable for small-animal PET studies in multiple nude mice xenografted with the A431 carcinoma cell line. (18)F-FLT was successfully synthesized on the EWOD microdevice coupled with an off-chip solid-phase extraction purification with a decayed-corrected radiochemical yield of 63% ± 5% (n = 5) and passed all of the quality control tests required by the U.S. Pharmacopeia for radiotracers to be injected into humans. We have successfully demonstrated the synthesis of several batches of (18)F-FLT on EWOD, starting with approximately 333 MBq of radioactivity and obtained up to 52 MBq (non-decay-corrected) of (18)F-FLT on cartridge purification. The specific activity of 2 representative preparations of (18)F-FLT synthesized on the EWOD chip were measured to be 1,800 and 2,400 GBq/μmol. The EWOD microchip and optimized synthesis method in combination represent an effective platform for synthesizing (18)F-FLT with high yield and of good quality for imaging. This compact platform, with configurable synthesis steps, could potentially form the basis of a stand-alone system that decouples PET probe production from the cyclotron and specialized radiochemistry facilities and increases diversity and flexibility in probe production.

Automated synthesis of [18F]FMISO on IBA Synthera®

In cancer cells hypoxia can cause resistance to both radio- and chemo-therapy. Being able to quantify, the degree of hypoxia in the cells is a useful tool in therapy planning. The positron emitting 1-[18F]fluoro-3-(2-nitro-1H-imidazol-1-yl)propan-2-ol ([18F]FMISO) is the most extensively used tracer for imaging hypoxia. Automated synthesis of [18F]FMISO was set up on IBA Synthera®. The precursor 1-(2′-nitro-1′-imidazolyl)-2-O-tetrahydropyranyl-3-O-p-toluenesulfonyl propanediol (NITTP) was heated at 100 °C for 10 min with [K/K 2.2.2.]+[18F]− and thereafter hydrolyzed with 0.1 M hydrochloric acid at 90 °C for 2 min. Purification was performed on solid-phase extraction (SPE) cartridges. [18F]FMISO was obtained in 50 ± 3 % (n = 6) radiochemical yield (decay-corrected) in 35 min synthesis time with radiochemical purity of ≥98 %. The use of disposable Integrated Fluid Processors (IFP™:s) and cartridge purification simplifies the handling and shortens the synthesis time. This is a no frills setup based on all commercially available materials and the synthesis is performed with minor changes from the FDG time-list.

One-pot multi-enzyme (OPME) chemoenzymatic synthesis of sialyl-Tn-MUC1 and sialyl-T-MUC1 glycopeptides containing natural or non-natural sialic acid

A series of STn-MUC1 and ST-MUC1 glycopeptides containing naturally occurring and non-natural sialic acids have been chemoenzymatically synthesized from Tn-MUC1 glycopeptide using one-pot multienzyme (OPME) approaches. In situ generation of the sialyltransferase donor cytidine 5′-monophosphate-sialic acid (CMP-Sia) using a CMP-sialic acid synthetase in the presence of an extra amount of cytidine 5′-triphosphate (CTP) and removal of CMP from the reaction mixture by flash C18 cartridge purification allow the complete consumption of Tn-MUC1 glycopeptide for quantitative synthesis of STn-MUC1. A Campylobacter jejuni β1–3GalT (CjCgtBΔ30-His6) mutant has been found to catalyze the transfer of one or more galactose residues to Tn-MUC1 for the synthesis of T-MUC1 and galactosylated T-MUC1. Sialylation of T-MUC1 using Pasteurella multocida α2–3-sialyltransferase 3 (PmST3) with Neisseria meningitidis CMP-sialic acid synthetase (NmCSS) and Escherichia coli sialic acid aldolase in one pot produced ST-MUC1 efficiently. These glycopeptides are potential cancer vaccine candidates.

A simple method for the determination of polycyclic aromatic hydrocarbons (pah) in edible oil employing solid phase extraction (SPE) cartridge purification

This paper reports a simple, fast, and inexpensive method for the determination of polycyclic aromatic hydrocarbons (PAH) in edible oils. The sample was dissolved in solvents, and a portion of the solution was loaded onto a solid phase extraction cartridge. The oil from the cartridge was washed away by isooctane/cyclohexane mixture and the absorbed PAHs were eluted with hexane/ dichloromethane mixture. GC-tandem MS was used to analyze 15 PAHs of EU priority in sesame oil and perilla oil. Analytical limits of determination (LOD) were 0.01–0.06 μg/kg, limits of quantitation (LOQ) were 0.03–0.17 μg/kg, and the recovery values ranged 55.1–105.0%. This method was validated using the certified reference material (CRM) and the error values ranged 2.06–4.30%. Twentyone commercial samples were analyzed to determine their PAHs contamination levels. The total concentration of the 15 PAHs in commercial samples ranged from not detected to 9.627 μg/kg. Only 1 sample had excessive benzo(a)pyrene content, which was more than 2.0 μg/kg.

A Method for Multiple Mycotoxin Analysis in Wines by Solid Phase Extraction and Multifunctional Cartridge Purification, and Ultra-High-Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry

An analytical method using two solid phase extractions and ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was developed for the identification and quantification of 14 mycotoxins (patulin, deoxynivalenol, aflatoxins B1, B2, G1, G2, M1, T-2 toxin, HT-2 toxin, zearalenone, fumonisins B1, B2, B3, and ochratoxin A) in domestic and imported wines. Mycotoxins were purified with an Oasis HLB cartridge, followed by a MultiSepTM #229 Ochra. As a result, sufficient removal of the pigments and highly polar matrices from the red wines was achieved. UHPLC conditions were optimized, and 14 mycotoxins were separated in a total of 13 min. Determinations performed using this method produced high correlation coefficients for the 14 mycotoxins (R > 0.990) and recovery rates ranging from 76 to 105% with good repeatability (relative standard deviation RSD < 12%). Twenty-seven samples of domestic and imported wines were analyzed using this method. Although ochratoxin A (OTA) and fumonisins (FMs) were detected in several samples, the FM levels were less than limits of quantification (LOQs) (1 μg/L), and even the largest of the OTA levels was below the EU regulatory level (2 μg/L). These results suggest that the health risk posed to consumers from the wines available in Japan is relatively low.