Cartridge Column Research Articles

Antagonistic activities against selected pathogens of a bacteriocin-producing lactic acid bacteria isolated from Balao-balao, a fermented rice-shrimp mixture

Lactic acid bacteria from a fermented rice-shrimp mixture traditionally known in the Philippines as Balao-balao were isolated in the present study. Screening of lactic acidproducing strains revealed that ten isolates showed promising inhibitory activities against test microorganisms namely Staphylococcus aureus BIOTECH 1634, Escherichia coli BIOTECH 1582, Bacillus subtilis BIOTECH 1679 and Vibrio harveyi SEAFDEC 010. Of interest was isolate PL12, a bacteriocin-producing strain which showed the highest inhibitory activity against the pathogens tested. Isolate PL12 was identified as Pediococcus pentosaceus (GenBank accession number MF353992) with 100% similarity by 16S rDNA sequence analyses. Excluding the effects of organic acids and hydrogen peroxide, the cell-free supernatant (CFS) of PL12 isolate exhibited strong antagonistic activities against test pathogens in an agar well diffusion assay. These results confirmed the isolate’s proteinaceous nature and are indicative of typical characteristics of bacteriocins. To further concentrate the proteins present in the CFS, ammonium sulfate precipitation followed by column purification (Sep-Pak C18 cartridge column) was performed. Positive antagonism of PL12 bacteriocin was observed in both Gram-positive and Gram-negative bacteria tested. The highest inhibitory activity was found against E. coli in every purification step. These results suggested that bacteriocin-producing PL12 isolate can be a promising preservative in the food industry and as probiotics in aquaculture since it possesses antagonistic activities against V. harveyi.

Characterization of collagen and its hydrolysate from southern bluefin tuna skin and their potencies as DPP-IV inhibitors

Collagen-derived peptides have been gaining interest due to their potential to act as DPP-IV inhibitors, which are considered to have antidiabetic effects. This study focused on extracting type I collagen from discarded southern bluefin tuna skin, confirming its structure and properties, and then measuring the ability of its hydrolysates to act as DPP-IV inhibitors. First, type I collagen was purified from southern bluefin tuna skin, and the constituent subunit was found to contain the α3(I) chain. Next, enzymatic hydrolysates were prepared, and their DPP-IV inhibitory activity measurements were examined and compared. Collagenase hydrolysate showed the highest DPP-IV inhibitory activity (71.8 ± 0.3 %), and considering digestive degradation, collagenase-pepsin-trypsin hydrolysate was prepared and separated into fractions via anion exchange chromatography, cartridge column, and HPLC. Notably, the 70 % methanol eluted fraction separated via cartridge column was found to have an IC50 of 0.26 ± 0.01 mg/ml. Subsequently, a novel peptide GPSGGGYDV with the highest DPP-IV inhibitory activity (IC50 value 82±0.0 µM) was purified from this fraction and found to be a competitive inhibitor of DPP-IV. This is the first study to investigate the DPP-IV inhibitory potential of type I collagen hydrolysate from southern bluefin tuna.

Convenient pre-separation method depends on negative charges suitable for glycan sequencing analysis.

For precise structural analysis of complex glycans, it is necessary to fractionate glycans based on acidity prior to liquid chromatography-mass spectrometry analysis. Conventional fractionation using high-performance liquid chromatography is time consuming and not high throughput. Therefore, we developed a rapid method for the fractionation using a small cartridge column. This enables rapid multi-sample processing for glycan sequencing.

Analytical Method for Melengestrol Acetate in Livestock Products Using LC-MS/MS

The present study verified that it is possible to analyze melengesterol acetate using the existing multi-residue method. Melengestrol acetate was extracted from livestock products using acidic acetonitrile acidified with acetic acid in the presence of n-hexane and anhydrous sodium sulfate. The crude extracts were cleaned up using an octadecylsilanized silica gel cartridge column. Separation by HPLC was performed using an octadecylsilanized silica gel column with linear gradient elution of 0.1 vol% formic acid and acetonitrile containing 0.1 vol% formic acid. For the determination of the analyte, tandem mass spectrometry with positive ion electrospray ionization was used. In recovery tests using four livestock products fortified with maximum residue limits levels of melengestrol acetate (0.001-0.02 mg/kg), the truenesses ranged from 82% to 100%, and the repeatabilities for the entire procedure ranged from 0.5 RSD% to 5.6 RSD%. In recovery tests using 11 livestock products fortified with 0.0005 mg/kg of melengestrol acetate, the truenesses ranged from 88% to 99%, and the repeatabilities ranged from 1.3 RSD% to 5.4 RSD%. The limit of quantification for melengestrol acetate in livestock products was 0.0005 mg/kg.

GC-MS Analysis of Tris(1-aziridinyl)phosphine Oxide Flame Retardants in Textile Products

Tris(1-aziridinyl)phosphine oxide (APO) used as flame retardant in textile products, such as curtains, carpets, and sleeping clothes, is prohibited in Japan under the "Act on the Control of Household Products Containing Harmful Substances." This study developed a GC-MS-based method to quantify APO more accurately and safely than the current official method. The APO in textile products was extracted with methanol, the extract was replaced with acetone instead of hexane as previously reported, and purified by florisil cartridge column. This cleanup method was instead of the harmful and carcinogenic dichloromethane used for open column to purify the sample in the official method, giving consideration to health of analysts. For accurate and sensitive quantification, deuterated compound, APO-d12, was used as a surrogate standard. The calibration curve displayed linearity within the 0.01-2.0 µg/mL range for APO. The detection limit for APO was 0.008 µg/g with S/N=5, which was 50 times more sensitive than the current detection limit of 0.4 µg/g, enabling the analysis of sufficiently low concentrations. The recoveries in non-treatment cloth and flame-retardant textiles were 73.5-126.6% and relative standard deviations were 3.3-24.6% when 2 µg APO was added to 0.5 g of samples, confirming that it can be analyzed satisfactorily. Thus, the developed method is applicable to textile products of various materials.

Multiplex Immunosuppressant (ISD) Method for the Measurement of Cyclosporine A, Tacrolimus, Sirolimus/Rapamycin, and Everolimus in Whole Blood Using MassTrak™ Kit.

Cyclosporine A, everolimus, sirolimus, and tacrolimus are the most commonly used immunosuppressant drugs in organ transplant and auto-immune patients. The narrow therapeutic window of these immunosuppressant drugs requires close monitoring of drug blood levels to ensure proper therapeutic response. A quick, robust high-throughput liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was introduced for monitoring whole blood levels of these immunosuppressant drugs with the use of the MassTrak™ Immunosuppressant kit. The assay was carried out in 96-well plate format and requires a simple precipitation step; after which, the supernatant is subjected to liquid chromatography separation (2min total run time) using a C18 Cartridge column. Identification and quantitation of cyclosporine A, everolimus, sirolimus, and tacrolimus was achieved by employing multiple reaction monitoring (MRM) in positive mode electrospray ionization (ESI). The method exhibits a linear measuring range from 10 to 1500ng/mL (Cyclosporine A), 1.0-30.0ng/mL (Everolimus), 1.0-26.0ng/mL (Sirolimus), and 1.0-30.0ng/mL (Tacrolimus) and has a within-run and between-run imprecision of <10%.

Production, isolation, and shipment of clinically relevant quantities of astatine-211: A simple and efficient approach to increasing supply

The alpha emitter astatine-211 (211At) is a promising candidate for cancer treatment based on Targeted Alpha (α) Therapy (TAT). A small number of facilities, distributed across the United States, are capable of accelerating α-particle beams to produce 211At. However, challenges remain regarding strategic methods for shipping 211At in a form adaptable to advanced radiochemistry reactions and other uses of the radioisotope. PurposeOur method allows shipment of 211At in various quantities in a form convenient for further radiochemistry. ProceduresFor this study, a 3-octanone impregnated Amberchrom CG300M resin bed in a column cartridge was used to separate 211At from the bismuth matrix on site at the production accelerator (Texas A&M) in preparation for shipping. Aliquots of 6 M HNO3 containing up to ≈2.22 GBq of 211At from the dissolved target were successfully loaded and retained on columns. Exempt packages (<370 MBq) were shipped to a destination radiochemistry facility, University of Texas MD Anderson Cancer Center, in the form of a convenient air-dried column. Type A packages have been shipped overnight to University of Alabama at Birmingham. Main findingsAir-dried column hold times of various lengths did not inhibit simple and efficient recovery of 211At. Solution eluted from the column was sufficiently high in specific activity to successfully radiolabel a model compound, 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (1), with 211At. The method to prepare and ship 211At described in this manuscript has also been used to ship larger quantities of 211At a greater distance to University of Alabama at Birmingham. Principal conclusionsThe successful proof of this method paves the way for the distribution of 211At from Texas A&M University to research institutions and clinical oncology centers in Texas and elsewhere. Use of this simple method at other facilities has the potential increase the overall availability of 211At for preclinical and clinical studies.

Determination of Flubendazole and Metabolite in Livestock Products Using LC-MS/MS

This study proposes a method to determine flubendazole and metabolite R35475 in livestock products using tandem mass spectrometry coupled with positive ion electrospray ionization. Acetone is used to extract flubendazole and metabolite R35475 from the livestock samples. These extracts were purified using an SCX cartridge column (500 mg). Furthermore, high-performance liquid chromatography was performed on an Inertsil ODS-4 column with a gradient formed using methanol and water, both of which contain 5 mmol/L of ammonium acetate. The recovery tests using bovine muscle, fat, liver, milk, and egg fortified at the maximum residue limits of analytes or 0.005 mg/kg revealed that the trueness (n=5) of flubendazole and metabolite R35475 ranged from 89.4 to 106.4% with a repeatability rate of 1.7-7.8%.

Development, Validation and Approbation Analytical Method for the Quantitative Determination of Taurine by HPLC-UV Method in the Test of Comparative Dissolution Kinetics

Introduction. Taurine is a non-proteinogenic amino acid. The molecule is involved in lipid metabolism, adsorbs fat-soluble vitamins, and its conjugates with bile acids contribute to the emulsification of fats in the intestine. Drugs, which include a taurine molecule, have anti-cataract, cardiotonic, metabolic effects, and also stimulate regeneration. Among the dosage forms, where taurine acts as an active substance, there is a solid dosage form – film-coated tablets. One of the methods for assessing the quality of solid dosage forms is a comparative dissolution kinetics test. High-performance chromatography with ultraviolet detection is a widely used method for quantification within the dissolution test, however, for taurine, which does not contain chromophore groups in its structure, this method is not directly applicable. To solve this problem, one can apply the method of pre-column derivatization, because of which an fragment is introduced into the structure, providing a bathochromic shift in the UV spectrum of the starting compound.Aim. Development, validation and approbation analytical method for the quantitative determination of taurine by high-performance chromatography with ultraviolet detection as part of a test comparative kinetics dissolution of taurine tablets with a dosage of 250 and 500 mg.Materials and methods. The following preparations were used for the analysis: taurine tablets, film-coated 250 mg and 500 mg, domestic production with a valid expiration date. The comparative dissolution kinetics test was carried out on a DT 126 Light instrument for the "Dissolution" test (ERWEKA GmbH, Germany). Chromatographic separation and detection were performed on a Nexera-i LC-2040 high-performance liquid chromatograph (Shimadzu Corporation, Japan) equipped with a column and sample thermostat, a degasser, an autosampler, and an ultraviolet detector. Detection was carried out at a wavelength of 254 nm after derivatization of the taurine molecule with 4-toluenesulfonyl chloride. Were used a Shim-pack Velox C18 5 μm 4.6 × 150 mm column (Shimadzu Corporation, Japan) and a Shim-pack Velox C18 EXP Guard Column Cartridge 5 μm 4.6 × 5 mm (Shimadzu Corporation, Japan). Primary data were processed using LabSolutions Single LC software (Shimadzu Corporation, Japan).Results and discussion. The optimal conditions for taurine derivatization have been selected, and a method for the quantitative determination of taurine by HPLC-UV in test comparative kinetics dissolution in three dissolution media: 0.1M hydrochloric acid solution with pH 1.2, acetate buffer solution with pH 4.5, phosphate buffer solution with pH 6.8, as well as in the quality control medium – purified water has been developed and validated. During the validation of the developed methodology, it was found that the validation characteristics are within the acceptance criteria in 4 dissolution media. The analytical range of the method was 0.05–1.2 mg/mL and allows the developed method to be used for the quantitative determination of tablets with a dosage of 250 mg and 500 mg as part of the test comparative kinetics dissolution. The method was tested in 4 dissolution media, in all media, there was a complete release in both dosages (more than 85 % by 30 minutes).Conclusion. The method was tested in three dissolution media: 0.1 M hydrochloric acid solution with pH 1.2, acetate buffer solution with pH 4.5, phosphate buffer solution with pH 6.8, as well as in the quality control medium – purified water. In all media, there was a complete release in both dosages (more than 85 % by 30 minutes).

Cover Feature: Continuous‐Flow Suzuki‐Miyaura Coupling in Water and Organic Solvents Promoted by Blends of Stabilized Convoluted Polymeric Palladium Catalysts and Polymeric Auxiliary Materials (Chem. Eur. J. 34/2023)

A heterogeneous flow Suzuki–Miyaura coupling has been carried out. A water or aqueous organic solution of aryl halides and arylboronic acids (left-hand side) was continuously injected into a flow column cartridge filled with convoluted polymeric Pd catalysts and stabilizing polymeric auxiliary materials (orange balls) along with sea sand (white balls). The products, which included liquid crystals, pharmaceutical compounds, and organic LED compounds, were eluted from the column (right-hand side). More information can be found in the Research Article by Y. M. A. Yamada and co-workers (DOI: 10.1002/chem.202300494).

Optimized approach for active peptides identification in Cerebrolysin by nanoLC-MS

Cerebrolysin (CBL) is a peptide-rich preparation made by hydrolysis and purified extraction of porcine brain. CBL contains various neuroprotective peptides, such as neurotrophic factor, nerve growth factor and ciliary neurotrophic factor, which can be used to treat neurodegenerative diseases. However, the active peptides in CBL had not been studied in depth. In this study, the following was carried out in order to investigate the active peptides in CBL. First, CBL samples were treated using organic reagents (acetonitrile and acetone) to precipitate the proteins and different solid phase extraction methods (MCX mixed-mode cartridges, C18 SPE cartridge columns and HILIC sorbent). Then the samples were analyzed using nanoLC-MS, followed by the identification of peptides using different sequence analysis software (PEAKS, pNovo and novor). Finally, bioinformatics analysis was performed to predict peptides with potential neuroprotective functions in CBL, such as anti-inflammatory and antioxidant peptides. Results showed that the number of peptides obtained by the MCX method coupled with PEAKS was the highest and the method was the most stable. Bioinformatic analysis of the detected peptides showed that two anti-inflammatory peptides (LLNLQPPPR and LSPSLRLP) and an antioxidant peptide (WPFPR) might be neuroprotective peptides in CBL. In addition, this study found that some peptides in CBL were present in myelin basic protein and tubulin beta chain. The results of this study for the detection of active peptides in CBL laid the foundation for the subsequent study of its active ingredients.

Simultaneous determination of glyphosate, glufosinate, and their metabolites in honey using liquid chromatography-tandem mass spectrometry and solid-phase extraction.

Here, we developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of residual glyphosate, glufosinate, and their metabolites N-acetylglyphosate (Gly-A), 3-methylphosphinicopropionic acid (MPPA) and N-acetylglufosinate (Glu-A) in honey using a mixed mode column of reversed-phase and anion exchange without derivatization. The target analytes were extracted from honey samples using water, cleaned up on a reverse phase C18 cartridge column and an anion exchange NH2 cartridge column, and quantified using LC-MS/MS. Glyphosate, Glu-A, Gly-A, and MPPA were detected in negative ion mode based on deprotonation, whereas glufosinate was detected in positive ion mode. The coefficients of determination (R2) of the calibration curve, calculated in the range of 1-20µg/kg for glufosinate, Glu-A, and MPPA, and 5-100µg/kg for glyphosate and Gly-A, were higher than 0.993. The developed method was evaluated using honey samples spiked with glyphosate and Gly-A at 25µg/kg and glufosinate, and MPPA and Glu-A at 5µg/kg, based on the maximum residue levels. The validation results show good recoveries (86-106%) and precision (< 10%) for all target compounds. The limit of quantification of the developed method is 5µg/kg for glyphosate, 2µg/kg for Gly-A, and 1µg/kg for glufosinate, MPPA and Glu-A. These results suggest that the developed method is applicable for quantifying residual glyphosate, glufosinate, and their metabolites in honey in compliance with Japanese maximum residue levels. Moreover, the proposed method was applied to the analysis of honey samples and glyphosate, glufosinate, and Glu-A were detected in some samples. The proposed method will be a useful tool for the regulatory monitoring of residual glyphosate, glufosinate, and their metabolites in honey.

LC-MS/MS analysis of elastin crosslinker desmosines and microscopic evaluation in clinical samples of patients with hypertrophy of ligamentum flavum

Ligamentum flavum (LF) pathologies often lead to severe myelopathy or radiculopathy characterized by reduced elasticity, obvious thickening, or worsened ossification. Elastin endows critical mechanical properties to tissues and organs such as vertebrae and ligaments. Desmosine (DES) and isodesmosine (IDES) are crosslinkers of elastin monomers called tropoelastin. These crosslinkers are potential biomarkers of chronic obstructive pulmonary disease. As a biological diagnostic tool that supplements existing symptomatic, magnetic resonance imaging scanning or radiological imaging diagnostic measures for LF hypertrophy and associated pathologies, an isotope-dilution liquid chromatography-tandem mass spectrometry method with selected reaction monitoring mode for the quantitation of DESs in human plasma, urine, cerebrospinal fluid (CSF), and yellow ligamentum was investigated. Isotopically labeled IDES-13C3,15N1 was used as an internal standard (ISTD) for DES quantitation for the first time. The samples plus ISTD were hydrolyzed with 6 N hydrochloric acid. Analytes and ISTD were extracted using a solid phase extraction cellulose cartridge column. The assays were repeatable, reproducible, and accurate with % CV ≤ 7.7, ISTD area % RSD of 7.6, and % AC ≤ (101.2 ± 3.90) of the calibrations. The ligamentum samples gave the highest average DES/IDES content (2.38 μg/mg) on a dry-weight basis. A high percentage of the CSF samples showed almost no DESs. Urine and plasma samples of patients showed no significant difference from the control (p-value = 0.0519 and 0.5707, respectively). Microscopy of the yellow ligamentum samples revealed dark or blue-colored zones of elastin fibers that retained the hematoxylin dye and highly red-colored zones of collagen after counterstaining with van Gieson solution. Thus, we successfully developed a method for DES/IDES quantitation in clinical samples.

S-50-2: ULTRAFAST LC-MS ANALYSIS FOR THE CHEMICAL ADHERENCE TESTING: SUB MINUTE RUN TIMES FOR A PANEL OF NINE CARDIOMETABOLIC MEDICATIONS

Objective: Non-adherence in hypertension can be as high as 30–45%. Chemical adherence testing (CAT) is the preferred method to assess non-adherence in European guidelines. New randomised controlled trials (RCTs), like the RADIANCE-HTN TRIO, have also started to implement CAT into their study framework to diagnoses non-adherence. Using high performance liquid chromatography (HPLC) in tandem mass spectrometry (MS/MS), existing quantitative urine CATs take &gt; 40 minutes. These provide a yes/no answer. Recent guidance has suggested run-time be an area of development, along with the research of quantitative assays in plasma. Translated from the field of therapeutic drug monitoring, UltraFast (&lt;1 minute) run times were explored using ultra performance short (UP)-LC columns with MS/MS for the detection and quantitation of nine cardiometabolic medications in plasma for use in CAT. UltraFast methods could increase clinical and research capacity while reducing cost. Design: An UltraFast quantitative CAT using UPLC-MS/MS was developed and optimised for the parallel detection of nine cardiometabolic medications in plasma. These medications were amlodipine, atenolol, atorvastatin, bisoprolol, edoxaban, enalapril, propranolol, ramipril, and saxagliptin. Methods: A mixed internal standard (IS; 10 ng/mL) was added to 100 μL of sample before the addition of 100 μL of water. The entire solution was added to pre-conditioned Oasis PRiME hydrophilic lipid balance (HLB) 96-well μElution solid phase extraction (SPE) plates. The loaded wells were washed (200 μL 5% methanol) and eluted (50 μL methanol/ acetonitrile) prior to UPLC-MS/MS analysis on a Waters Xevo TQ-XS triple quadrupole system. Sub 45 s run times were achieved using a Raptor Biphenyl Guard column cartridge (5 x 2.1 mm, 2.7 μm) as the UPLC column, used in reverse phase, and pumped at a 1.4 mL/min flow rate. Five replicate calibration curves were extracted over the range 0.01–500 ng/mL to assess model fits and detection limits. Results: All medications in plasma had lower limits of detection (LOD) between 0.01 ng/mL (atorvastatin) and 20 ng/mL (amlodipine). Optimum calibration curves were obtained. These were a mixture of quadratic and linear models. R2 ranged from 0.837 (enalapril) to 0.971 (atorvastatin). Clear chromatographic separation was achieved with the first eluted peak was atenolol, detected at 3 s. The last eluted peak was edoxaban at 22 s. Quantitation was possible over the range 0.01–500 ng/mL. Conclusion: A &lt;45 second UPLC-MS/MS run time was achieved for a panel of nine cardiometabolic medications. LODs were well within the therapeutic range of interest, and quantitation was made possible over 0.01–500 ng/mL, the therapeutic range of interest. This method could be applied in clinical laboratories for same day adherence testing, or to large RCTs for their timely processing.

Bilirubin Removal by Plasmafiltration-Adsorption: Ex vivo Adsorption Kinetics Model and Single Case Report

Background: Extracorporeal removal of bilirubin in patients with severe liver dysfunction is a key blood purification strategy. We conducted an ex vivo study to assess the quantitative capacity to remove bilirubin from plasma of a novel adsorptive cartridge. Methods: We studied a downscaled module of the BS330 Plasma Bilirubin Adsorption Column Cartridge (Jafron Biomedical, Zhuhai City, China) to minimize the plasma requirement in an ex vivo circulation using a solution of hyperbilirubinemic plasma. We measured the bilirubin concentration gap (ΔC) between inlet (Cp_in) and outlet (Cp_out) of the unit and we calculated the removal ratio (RR) as mass adsorbed at different time points. Moreover, we compared the ex vivo model with the bilirubin adsorption kinetics in a patient with acute on chronic liver failure treated with the BS330 cartridge. Results: Bilirubin concentration change across the cartridge at 30 min was 16.5%, and cartridge saturation was reached at 750 min. We used a minimodule downscaled to 1:3 and containing approximately 131 g of BS330 sorbent beads: the device retained 759 mg of bilirubin with a RR of 78.1% and a RR of 42.6% at 120 min. Thus, the adsorption capacity was 5.76 mg of bilirubin per gram of sorbent. Bilirubin adsorption kinetics in our clinical case with a full-scale unit shows a coherent trend with a total bilirubin mass adsorbed after 180 min of 470 mg. Discussion: Our findings provide the first assessment of bilirubin adsorption in an ex vivo model of plasma perfusion and can be used to design interventional studies in humans, providing guidance for an adequate prescription of treatment frequency and duration.

MXene as a novel cartridge for N-glycan enrichment

In this study, we applied MXene as column cartridge for N-glycan enrichment from human samples with a focus on the analysis of sialic acid linkages using a derivatisation protocol followed by glycan analysis via Matrix Assisted Laser Desorption Ionisation-Time Of Flight Mass Spectrometry (MALDI-TOF-MS). The MXene-based cartridge enriches a higher number of glycans (i.e., sialylated and bisecting N-glycans) when compared to the commercial HILIC columns. We demonstrate the strong potential of MXene as a stationary phase in MS glycomic analysis.

A zirconia-based column chromatography system optimized for the purification of IgM from hybridoma culture supernatants

By using EDTPA-modified zirconia particles that selectively adsorb immunoglobulins in a column, we developed a chromatography separation system for efficient concentrating and purifying of IgM from hybridoma culture supernatants. Hybridoma culture supernatants containing IgMs were diluted 3-fold with 10 mM phosphate buffer (pH 7.0) and passed through the column. During this process, zirconia particles selectively adsorbed these IgMs, and most of the contaminating proteins flowed out into the flow-through. The adsorbed IgMs were easily eluted with a small volume of 400 mM phosphate buffer (pH 8.0), and high-concentration IgM solutions were prepared. Subsequent simple processing using a Capto™ Core 400 cartridge column provided highly purified IgM. The operation is easy, and the activity of IgM is maintained because the purification process is performed using only neutral ranges of phosphate buffers. Here, we showed that anti-globoside and anti-CDw75 IgM purified by this method can be used to stain cervical cancer and Burkitt lymphoma cells that specifically express these respective tumor-associated carbohydrate antigens.

Determination of chlorpropham residues in animal-derived foods by solid phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry

建立了固相萃取-超高效液相色谱-串联质谱法(SPE-UHPLC-MS/MS)测定动物源食品中氯苯胺灵残留的分析方法。动物源食品经乙腈溶液提取、正己烷脱脂、ProElut PLS固相萃取柱富集净化,采用C18色谱柱进行分离,以0.2%(v/v)甲酸水溶液和乙腈为流动相进行梯度洗脱,采用电喷雾电离、正离子模式扫描,多反应监测模式(MRM)检测,基质匹配标准曲线外标法定量。研究通过对不同填料的固相萃取柱的考察,最终选择了ProElut PLS固相萃取柱,其能对动物源食品复杂基质中的氯苯胺灵进行有效富集和净化;通过考察3种规格的C18柱对氯苯胺灵的保留能力和出峰效果,选择了Agilent ZORBAX SB-C18(150 mm×2.1 mm, 5 μm)作为氯苯胺灵的分离色谱柱;通过考察氯苯胺灵在正负两种质谱电离模式下的响应情况,选择了正离子模式,确定氯苯胺灵一级质谱准分子离子和相应的碎片离子。结果表明:氯苯胺灵在0.5~100.0 μg/L范围内呈良好的线性关系,相关系数(r2)均不低于0.9929;方法定量限(LOQ)为3 μg/kg(S/N≥10);以猪肉、牛奶、牛肉、鸡肉、鸭肉、鸡蛋、鸡胗、鸭蛋、猪腰、猪肝、牛肝、羊肉、鸭胗共13种动物源食品为基质,在0.003、0.006、0.060 mg/kg添加水平下,氯苯胺灵的平均回收率为74.9%~97.6%,相对标准偏差(RSD)为2.9%~9.5%(n=6)。本方法前处理简便易行、基质干扰小、灵敏度高、准确性高,适用于多种动物源食品中氯苯胺灵的定性和定量检测。

Development of an Analytical Method for Simultaneous Determinationof Quinolones and Tetracyclines in Livestock and Fishery Products

In this study, we developed an analytical method for simultaneous determination of 14 quinolones and 4 tetracyclines in livestock and fishery products using LC-MS/MS. The analytes were extracted from food samples with citrate buffer (containing EDTA)-methanol-acetonitrile (3 : 1 : 1, v/v/v) in the presence of n-hexane, and the extract was purified with an Oasis PRiME HLB cartridge column. It was suggested that this analytical method can also extract analytes from solid samples containing fat by using n-hexane. In addition, using methanol-acetonitrile (3 : 7, v/v) containing 0.1 vol% formic acid as an eluent from the cartridge column, the purification effect could be improved, while minimizing the impairment of the recovery rate. As a result of the validation using six types of food samples, trueness (accuracy) was 70.6%-113.8%, the RSD of repeatability was 9.0% or less, and the RSD of within-laboratory reproducibility was 15.5% or less. Using this approach, the standard values mentioned in the Japanese guideline were successfully met.

Preparation of a novel cartridge column for solid phase extraction, used for separation of some heavy metal

This study included the removal of heavy metal ions by developing the solid-phase extraction method and preparing separation columns in order to isolate unwanted water pollutants. Single-use separator columns contain a modified extraction block consisting of (organic azo reagent 6-MBTAMP with chitosan) low the cost and this mass are saturated with the aforementioned organic reagent for the purpose of increasing the extraction surface area by increasing the effective aggregates. The modified extraction mass was characterization by means of the X-ray diffraction technique and several sharp crystal peaks appeared for us, and the highest of these peaks were equal to 38.81.