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1.
Clin Exp Metastasis ; 39(1): 109-115, 2022 02.
Article in English | MEDLINE | ID: mdl-34698993

ABSTRACT

Unlike in breast cancer and melanoma, sentinel lymph node mapping in colon cancer is primarily used as an aid to the pathologist for accurate nodal staging. The study was undertaken to review the incidence of micro-metastasis and its impact on survival when treated with chemotherapy. The study was also undertaken to see if SLNM could guide limited colon resection in early T stage tumor as a paradigm shift. SLNM was done by subserosal injection of a blue dye. SLNs were ultra-staged by multilevel sectioning and remaining Specimen was then examined by conventional method. For the last 245 patients the specimen was divied ex vivo into two segments as segment A containing the tumor bearing portion of the colon and SLNs with attached mesentery, while segment B include distal part of the colon with attached mesentery. Nodal staging was separately examined. Of the 354 Pts, SLNM was successful in 99.9% of Pts with an average no of SLN/ Pt = 2.8 and total nodes 17.8/pt. Survival was directly related negatively with stage and nodal status. Pts with +ve LN did much better with chemotherapy than without chemotherapy. With 245 Pts, specimen A Vs B, no Pts had +ve node in specimen B with -ve LN in specimen A. SLNM results in more node/Pt, more positive node/Pt ,and more micro-metastasis who when treated with chemotherapy survive longer. Limited segmental resection in early T stage is possible when done with guidance by SLNM without compromising biology.


Subject(s)
Colonic Neoplasms , Sentinel Lymph Node , Colonic Neoplasms/pathology , Colonic Neoplasms/surgery , Humans , Lymph Nodes/pathology , Lymph Nodes/surgery , Lymphatic Metastasis/pathology , Neoplasm Staging , Sentinel Lymph Node/pathology , Sentinel Lymph Node/surgery , Sentinel Lymph Node Biopsy/methods
2.
J Immunol Methods ; 499: 113150, 2021 12.
Article in English | MEDLINE | ID: mdl-34560071

ABSTRACT

Anti-N-methyl-d-aspartate receptor (NMDAR) antibodies are most frequently detected in autoantibody-related autoimmune encephalitis. Anti-NMDAR encephalitis mainly affects young women with ovarian teratoma, including acute to subacute onset of psychosis, seizures, consciousness disturbance, dyskinetic involuntary movements, autonomic dysfunction, and others. Diagnosis is based on the detection of anti-NMDAR autoantibodies in cerebrospinal fluid (CSF). The autoantibody recognizes the conformational epitope of the NMDA receptor. NMDA receptors contain hetero-tetramers of GluN1 (NR1) and GluN2/3 (NR2/3), in which GluN1 is essential to form functional receptors on the synaptic membrane in the brain. Thus, the autoantibodies are detected using neurons or culture cells expressing conformational receptors on their cell membrane, the natural form in the brain. The antibodies detected using artificial GluN1 monosubunit expressing cells as the antigens have been widely used for anti-NMDAR-antibody test. In the present study two detection systems were compared, a live-cell-based assay using human embryonic kidney (HEK) 293 cells expressing both of GluN1 and GluN2B, and a commercially available GluN1-monotransfected HEK cell biochip system. As the result, both the methods were equivalent, and the clinical features of both groups were similar, suggesting both tests have equal clinical significance.


Subject(s)
Autoantibodies/analysis , Adult , Autoantibodies/cerebrospinal fluid , Autoantibodies/immunology , Female , HEK293 Cells , Humans , Male , Receptors, N-Methyl-D-Aspartate/immunology
3.
ACS Omega ; 4(7): 12325-12332, 2019 Jul 31.
Article in English | MEDLINE | ID: mdl-31460350

ABSTRACT

The quantities of (5S)- and (5R)-5,6-dihydrothymidine (total DHdThd) in frozen beef liver samples were compared between those irradiated by an electron beam (EB) and those subjected to γ-irradiation. DNA extracted from the samples was enzymatically digested to nucleosides and analyzed by liquid chromatography-tandem mass spectrometry for total DHdThd and 2'-deoxythymidine (dThd). Total DHdThd was formed radiospecifically and dose-dependently and the dose-response curves of the ratio of total DHdThd to dThd (total DHdThd/dThd) were similar for both the EB- and γ-irradiated samples. The total DHdThd/dThd was stable after long-term storage (4 months) at -20 °C and the followed heat treatment in a microwave oven. The total DHdThd/dThd could be a robust marker and is equally effective at quantitating both EB- and γ-ray irradiation history. The irradiation doses of raw beef liver samples were estimated using the dose-response curves of the total DHdThd/dThd of other irradiated samples. The ratio of the estimated dose to the actual dose was 0.74-1.30 in the irradiation range of 4.67-7.62 kGy.

4.
Shokuhin Eiseigaku Zasshi ; 59(3): 146-150, 2018.
Article in English | MEDLINE | ID: mdl-30033992

ABSTRACT

We carried out a collaborative study in six laboratories to confirm the universality of the enhancing effect of co-existing reference pesticides on the GC-MS peak response to a target pesticide (malathion, procymidone, or flucythrinate). First, we confirmed the response enhancement of the target pesticides with increasing numbers of co-existing reference pesticides in solution. Then, using diluted green soybean matrix, we analyzed the target pesticides with two types of matrix-matched calibration, containing the target pesticides or 166 other pesticides. In both cases, the response-enhancing effect of co-existing pesticides was confirmed in all laboratories. The enhancement was reduced by addition of green soybean matrix to the sample and calibration solutions. Our results show that it is necessary to estimate the peak response-enhancing effect of co-existing pesticides in the calibration solution to obtain accurate results with GC-MS determination. The enhancing effect could be reduced by addition of food matrix to the sample and calibration solutions.


Subject(s)
Food Analysis/methods , Pesticide Residues/analysis , Pesticides/analysis , Calibration , Gas Chromatography-Mass Spectrometry
5.
Anal Bioanal Chem ; 410(13): 3145-3160, 2018 May.
Article in English | MEDLINE | ID: mdl-29556739

ABSTRACT

Polyethylene glycol 300 is commonly used as a base material for "analyte protection" in multiresidue pesticide analysis via gas chromatography-mass spectrometry. However, the disadvantage of the co-injection method using polyethylene glycol 300 is that it causes peak instability in α-cyano pyrethroids (type II pyrethroids) such as fluvalinate. In this study, we confirmed the instability phenomenon in type II pyrethroids and developed novel analyte protectants for acetone/n-hexane mixture solution to suppress the phenomenon. Our findings revealed that among the examined additive compounds, three lipophilic ascorbic acid derivatives, 3-O-ethyl-L-ascorbic acid, 6-O-palmitoyl-L-ascorbic acid, and 6-O-stearoyl-L-ascorbic acid, could effectively stabilize the type II pyrethroids in the presence of polyethylene glycol 300. A mixture of the three ascorbic acid derivatives and polyethylene glycol 300 proved to be an effective analyte protectant for multiresidue pesticide analysis. Further, we designed and evaluated a new combination of analyte protectant compounds without using polyethylene glycol or the troublesome hydrophilic compounds. Consequently, we obtained a set of 10 medium- and long-chain saturated fatty acids as an effective analyte protectant suitable for acetone/n-hexane solution that did not cause peak instability in type II pyrethroids. These analyte protectants will be useful in multiresidue pesticide analysis by gas chromatography-mass spectrometry in terms of ruggedness and reliable quantitativeness. Graphical abstract Comparison of effectiveness of the addition of lipophilic derivatives of ascorbic acid in controlling the instability phenomenon of fluvalinate with polyethylene glycol 300.

6.
J Agric Food Chem ; 65(42): 9342-9352, 2017 Oct 25.
Article in English | MEDLINE | ID: mdl-28954193

ABSTRACT

A rapid and reliable method for determining irradiation histories of ground beef and prawns was developed on the basis of a method for determining the irradiation history of beef liver by liquid chromatography-tandem mass spectrometry (LC-MS/MS) of 5,6-dihydrothymidine (DHdThd). Improvements in the method included the following: (1) 50% ethanol precipitation in the DNA extraction step was conducted before the RNase step, (2) snake venom phosphodiesterase I was used for DNA digestion to boost liberation of DHdThd, and (3) a matrix-matched calibration curve was used for determining DHdThd by LC-MS/MS analysis. This method successfully determined irradiation histories of ground beef and prawns. Furthermore, a close correlation between the formation of DHdThd and 2-alkylcyclobutanones, which are an established index of irradiation histories, was observed in ground beef. DHdThd in DNA could be a promising candidate for a new index of irradiation histories of various foods.


Subject(s)
Chromatography, Liquid/methods , Decapoda/chemistry , Meat/analysis , Shellfish/analysis , Tandem Mass Spectrometry/methods , Thymidine/analogs & derivatives , Animals , Cattle , Decapoda/radiation effects , Food Irradiation , Meat/radiation effects , Shellfish/radiation effects , Thymidine/analysis
7.
J Sep Sci ; 40(6): 1293-1300, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28106327

ABSTRACT

In multiresidue pesticide analysis using gas chromatography, it has long been recognized that an increase in the number of pesticides present in a standard solution can result in an enhancement of the peak responses of certain pesticides. Despite being widely acknowledged, this phenomenon has been rarely studied and is poorly understood. In this study, the authors have tentatively called this phenomenon the "matrix-like effect" and demonstrated it clearly using gas chromatography with tandem mass spectrometry. Five selected pesticides, namely, omethoate, terbufos, malathion, procymidone, and permethrin, and four internal standard candidates, namely, triphenyl phosphate, naphthalene-d8 , phenanthrene-d10 , and fluoranthene-d10 , were used to evaluate the matrix-like effect following the addition of 58, 108, and 166 other pesticides. With the exception of naphthalene-d8 , the responses of all evaluated pesticides and internal standard candidates were dramatically enhanced by the addition of up to 166 coexisting pesticides. The relative response factors of the five pesticides to each internal standard candidate were not constant under the conditions studied, meaning that these internal standard candidates did not adequately compensate for the matrix-like effect, at least for the five evaluated pesticides. The results revealed that the presence of various mixtures of pesticides in standard solutions might act as an unintentional analyte protectant, that is, some sort of troublesome "quasi-matrix."

8.
Food Chem ; 216: 186-93, 2017 Feb 01.
Article in English | MEDLINE | ID: mdl-27596408

ABSTRACT

A method for detecting irradiation histories of raw beef livers was developed by measuring 5,6-dihydrothymidine (DHdThd) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Liver DNA was extracted using phenol-chloroform extraction followed by precipitation in 50% ethanol. DNA was then enzymatically digested and nucleosides were purified using an OASIS MCX column. DHdThd and thymidine (dThd) contents of resulting test solutions were analyzed using LC-MS/MS. DHdThd was detected specifically after γ-irradiation. Concentration ratios of DHdThd to dThd in the test solutions increased dose-dependently after irradiation at 1.0-11.3kGy, which included the practical dose for sterilization of 2-7kGy. Dose-response curves from beef livers of individual animals almost overlapped. Thus, this method is a candidate for the detection of irradiation histories of foods from which DNA can be extracted.


Subject(s)
Chromatography, Liquid/methods , Liver/radiation effects , Tandem Mass Spectrometry/methods , Thymidine/analogs & derivatives , Animals , Cattle , DNA/analysis , Liver/chemistry , Thymidine/analysis
9.
Jpn J Infect Dis ; 70(4): 362-367, 2017 07 24.
Article in English | MEDLINE | ID: mdl-27795474

ABSTRACT

Japanese encephalitis virus (JEV) is a flavivirus, responsible for over 30,000 annual cases of encephalitis worldwide, with a mortality rate of approximately 30%. Therefore, it is important to examine the distribution of mosquitos carrying JEV in the fields, even though recently, the number of Japanese encephalitis cases has been approximately 5 per year in Japan. We report the seasonal dynamics of mosquitoes between 2010 and 2014 in Ishikawa Prefecture, Japan. We collected 39,308 female adult mosquitoes, 98.2% of which were classified as Culex tritaeniorhynchus Giles. We identified JEV genomic RNA belonging to genotype 1 from the homogenate of Cx. tritaeniorhynchus, collected during our study using reverse transcription-PCR and nucleotide sequencing techniques. Our results indicate that mosquito vectors for JEV are distributed not only in areas in Ishikawa, but also throughout Japan, and the results suggest that we must be careful regarding JEV outbreaks in Japan in the future.


Subject(s)
Encephalitis Virus, Japanese/isolation & purification , Mosquito Vectors/growth & development , Mosquito Vectors/virology , Animals , Female , Japan , Mosquito Vectors/classification , Population Dynamics , RNA, Viral/analysis , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Seasons , Sequence Analysis, DNA
10.
Shokuhin Eiseigaku Zasshi ; 56(4): 178-84, 2015.
Article in Japanese | MEDLINE | ID: mdl-26346863

ABSTRACT

Quantitative methods using the matrix-matched standard solutions approach are widely used for multi-residue pesticide determination by GC-MS/MS to deal with the issue of matrix effects. However, preparing matrix-matched standard solutions in analyses of many kinds of samples is very time-consuming. In order to solve this problem, a method that employs general matrix standard solutions has been developed using polyethylene glycol (PEG), extract of vegetables-fruit juice (VFJm) and triphenyl phosphate (named the PEG-VFJm method). Here, a validation study for 168 pesticides was performed on three kinds of samples [potato, spinach and apple] at concentrations of 0.010 and 0.050 µg/g. In these three commodities, 144 to 158 pesticides satisfied the required criteria using the matrix-matched method and 129 to 149 pesticides satisfied the same criteria using the PEG-VFJm method. Our results suggest that application of general matrix standard solutions would enable rapid and effective analyses of pesticides.


Subject(s)
Chromatography, Gas/methods , Food Analysis/methods , Food Contamination/analysis , Fruit/chemistry , Pesticide Residues/analysis , Tandem Mass Spectrometry/methods , Vegetables/chemistry , Organophosphates , Pesticide Residues/isolation & purification , Polyethylene Glycols , Solutions
11.
Shokuhin Eiseigaku Zasshi ; 54(3): 237-49, 2013.
Article in Japanese | MEDLINE | ID: mdl-23863370

ABSTRACT

A validation study was conducted on a rapid multiresidue method for determination of pesticide residues in vegetables and fruits by LC-MS/MS. Pesticide residues in the vegetables or fruits were extracted with acetonitrile in a disposable tube using a homogenizer, followed by salting out with anhydrous magnesium sulfate and sodium chloride in the presence of citrate salts for buffering. The extract was purified with a double-layered cartridge column (graphite carbon black/primary secondary amine silica gel; GCB/PSA). For citrus fruits a purification step with a C18 column was added (this column was connected to the GCB/PSA column). After removal of the solvent, the extract was resolved in methanol/water and analyzed by means of LC-MS/MS. The method was validated according to the method validation guideline of the Ministry of Health, Labour and Welfare of Japan; recovery tests were performed on 8 kinds of vegetables and fruits [cabbage, cucumber, Japanese radish, onion, potato, spinach, Amanatsumikan (a citrus fruit) and apple] by fortification of 161 pesticide residues at the concentrations 0.01 and 0.05 µg/g (each concentration of pesticide residue was extracted from 2 samples on 5 separate days). The trueness of the method for 127 pesticides in all 8 commodities was 70-120% with satisfactory repeatability and within-run reproducibility. This method is concluded to be applicable for determination of pesticide residues in vegetables and fruits.


Subject(s)
Chromatography, Liquid/methods , Food Analysis/methods , Food Contamination/analysis , Fruit/chemistry , Pesticide Residues/analysis , Pesticide Residues/isolation & purification , Tandem Mass Spectrometry/methods , Vegetables/chemistry
12.
Article in English | MEDLINE | ID: mdl-23549104

ABSTRACT

PURPOSE OF THE STUDY: The present study aimed to compare the voice quality after each type of cordectomy with that after radiotherapy (RT) or chemoradiotherapy (CRT) for early glottic carcinoma. PROCEDURES: The GRBAS perceptive scale [consisting of 5 domains: grade (G), roughness (R), breathiness (B), asthenia (A), and strain (S)], aerodynamic tests and acoustic analyses, and the Voice Handicap Index questionnaire were evaluated for 58 laser cordectomy cases and 40 RT or CRT cases. Multiple comparison tests were conducted between each type of cordectomy and RT or CRT. RESULTS: No statistical difference was found between type I/II cordectomy and RT for T1 glottic carcinoma (T1RT), whereas T1RT showed a significantly better outcome than type III cordectomy (G score: p = 0.016, maximum phonation time: p < 0.01, mean flow rate: p < 0.01). Type IV cordectomy was equivalent to RT or CRT for T2 glottic carcinoma (T2RT/CRT), while types V and VI showed a worse voice quality than T2RT/CRT (G score: p = 0.038 to type VI, B score: p = 0.025 to type V and p = 0.032 to type VI, A score: p = 0.017 to type VI). CONCLUSIONS: Voice quality after laser cordectomy differs according to the type of cordectomy. Surgeons should inform patients about the expected voice quality after each treatment modality.


Subject(s)
Glottis , Laryngeal Neoplasms/therapy , Laser Therapy , Vocal Cords/surgery , Voice Quality , Aged , Aged, 80 and over , Chemoradiotherapy , Female , Humans , Laser Therapy/methods , Male , Middle Aged , Phonation , Retrospective Studies
13.
Shokuhin Eiseigaku Zasshi ; 54(6): 392-6, 2013.
Article in Japanese | MEDLINE | ID: mdl-24389469

ABSTRACT

If pesticide residues are detected at over the uniform limit (0.01 ppm) in processed foods, the maximum residue limits of pesticides in each ingredient should be considered. For that purpose, analysis of pesticide residues in the ingredients would be required, but in many cases it is difficult to obtain ingredients from the same lot, or the processed foods may have been manufactured overseas. Thus, a means of estimating pesticide concentrations in ingredients before processing would be important. In this study, we estimated the concentration of paclobutrazol, which was detected in LM pickles (LMPs), that would have been present in Takana (LM; mustard leaf) before processing. The LMPs mainly consisted of LM and seasoning liquid (SL), and other ingredients (sesame seeds or red pepper) accounted for less than 0.2% (w/w) of the LMPs. The LM and SL were separated and their paclobutrazol concentrations were determined. The concentration of paclobutrazol in the SL was approximately 1/10 of that detected in LM. Loss of water from LM during processing was taken into account to calculate the content of paclobutrazol in LM before processing, based on the analytical result of processed LM.


Subject(s)
Food Analysis/methods , Food Contamination/analysis , Food Handling , Pesticide Residues/analysis , Triazoles/analysis , Maximum Allowable Concentration , Pesticide Residues/standards
14.
Shokuhin Eiseigaku Zasshi ; 54(6): 426-33, 2013.
Article in Japanese | MEDLINE | ID: mdl-24389475

ABSTRACT

A rapid multi-residue method for determination of pesticide residues in processed foods manufactured from agricultural products was examined. Five mL water was added to 5 g sample in a polypropylene tube, and the tube was left to stand at room temperature for 30 min. Then, 20 mL acetonitrile was added to the sample. The mixture was homogenized in a high-speed homogenizer, followed by salting out with 1 g NaCl and 4 g anhydrous MgSO4. After centrifugation, the organic layer was purified on a graphitized carbon/PSA cartridge column. After removal of the solvent, the extract was resolved in methanol-water and analyzed with LC-MS/MS. The recoveries of 93 pesticides fortified into 5 kinds of processed foods [Chinese cabbage kimchi, marmalade, raisin, umeboshi (pickled plum) and worcester sauce] were examined at the concentrations of 0.02 and 0.1 µg/g (n=5). The recoveries of 61 pesticides in all foods were 70-120% with relative standard deviation below 20% at both concentrations. Seventy-four processed foods obtained from markets in Japan were examined with this method. Pesticide residues over the maximum residue limit (0.01 µg/g) were detected in 2 processed foods.


Subject(s)
Chromatography, High Pressure Liquid/methods , Crops, Agricultural/chemistry , Food Analysis/methods , Food Contamination/analysis , Food Handling , Pesticide Residues/analysis , Tandem Mass Spectrometry/methods , Maximum Allowable Concentration
15.
Shokuhin Eiseigaku Zasshi ; 53(4): 183-93, 2012.
Article in Japanese | MEDLINE | ID: mdl-23132358

ABSTRACT

A rapid and simple multi-residue method for determination of pesticides has been applied to drinking water and beverages. To a disposable polypropylene tube containing 10.0 g sample, 20 mL acetonitrile was added and the mixture was shaken vigorously for 1 min to extract pesticides. Then, 1 g sodium chloride and 4 g magnesium sulfate anhydrous were added, followed by vigorous shaking for 1 min and centrifugation to obtain the organic phase. The organic phase was processed with a graphite carbon black/PSA solid phase column. After concentration and reconstitution with 25% methanol containing aqueous solution, the test solution was analyzed with LC-MS/MS. Recovery tests of 91 pesticides fortified (0.02 µg/g) in 35 kinds of drinking water and beverages were conducted. The decline of recoveries in alcoholic beverages is considered to be due to the increase of organic phase volume owing to ethanol included in the alcoholic beverages. A simulation study was carried out with simulated alcoholic beverages, which consisted of 50% grape juice, with various amounts of ethanol and water, to examine pesticides recoveries and volume of the organic phase. The results suggested this method would be applicable both to alcoholic beverages containing less than 10% ethanol and to alcoholic beverages containing over 10% ethanol after dilution with water to below 10% ethanol prior to the addition of acetonitrile. A sample could be processed and analyzed by LC-MS/MS within 2 h. Thus, this method should be useful for monitoring and screening pesticide residues in drinking water and various beverages.


Subject(s)
Beverages/analysis , Chromatography, Liquid/methods , Drinking Water/analysis , Pesticide Residues/analysis , Tandem Mass Spectrometry/methods , Time Factors
16.
J Neurol Neurosurg Psychiatry ; 82(12): 1360-4, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21665917

ABSTRACT

OBJECTIVE: To analyse clinicoepidemiological features of neuromyelitis optica in a large cohort and to compare the differences between onset age, gender and clinical phenotypes. METHODS: Antiaquaporin-4 antibody (AQP4-ab) levels were tested in 2366 serum samples of patients diagnosed as having central nervous system inflammatory demyelinating disorders by their referring physicians. AQP4-ab was measured by indirect immunofluorescence staining using human AQP4-transfected HEK 293 cells. A blinded analysis was performed and was combined with clinical information. RESULTS: A total of 583 patients (91.4% women) were AQP4-ab-positive. The average onset age was 42.9±15.9 years. According to MRI studies, spinal-cord lesions were detected in 85.3% of the patients, longitudinally extensive transverse myelitis in 72.7% and cerebral lesions in 51.1%. Unilateral or bilateral blindness was observed in 16.2% of patients, 19.8% were associated with Sjögren syndrome, and 13.6% were associated with thyroid diseases. Myelin basic protein was detected in the cerebrospinal fluid of 57.5% patients. In addition, men presented with an older onset age, a greater number of brainstem MRI lesions and positive myelin basic protein in the cerebrospinal fluid. All child-onset patients (<15 years, n=9) presented with optic neuritis as the first symptom, while older-onset patients presented with myelitis. Twenty patients initially developed limited brain lesions, and seven of these patients did not develop optic or spinal lesions during the 1-5-year follow-up period. CONCLUSIONS: The clinical characteristics of AQP4-ab-positive patients were similar. However, optic neuritis was more common in paediatric patients, while myelitis was more common in older patients. A small number of patients exhibited only cerebral, brainstem, or cerebellar lesions during the initial several years and lower Extended Disability Status Scale scores.


Subject(s)
Neuromyelitis Optica/diagnosis , Neuromyelitis Optica/epidemiology , Adult , Age of Onset , Antibodies/blood , Aquaporin 4/immunology , Biomarkers/blood , Biomarkers/cerebrospinal fluid , Brain/pathology , Cohort Studies , Female , Humans , Japan/epidemiology , Magnetic Resonance Imaging/methods , Male , Middle Aged , Neuroimaging/methods , Neuromyelitis Optica/blood , Neuromyelitis Optica/cerebrospinal fluid , Neuromyelitis Optica/immunology , Neuromyelitis Optica/pathology , Phenotype , Sex Characteristics , Spinal Cord/pathology
17.
Shokuhin Eiseigaku Zasshi ; 50(5): 198-207, 2009 Oct.
Article in Japanese | MEDLINE | ID: mdl-19897945

ABSTRACT

A rapid and simple multiresidue method has been established for determination of pesticide residues in processed foods by GC/MS. The pesticides were extracted with ethyl acetate in the presence of anhydrous MgSO(4) in a disposable tube, using a homogenizer. The extract was concentrated and reconstituted in hexane, followed by acetonitrile-hexane partition to remove lipids. The acetonitrile layer was cleaned up with a double-layered SPE cartridge column (graphite carbon black/PSA silica gel). After removal of the solvent, the residue was dissolved in acetone. The test solution was subjected to GC/MS in the EI mode. Recovery tests of 222 pesticides from five kinds of processed foods (dumpling, curry, French fries, fried chicken, fried fish) were performed at two different fortification levels of 0.02 and 0.1 microg/g, and 100 pesticides showed acceptable recovery (70-120%) with low relative standard deviation (

Subject(s)
Food Analysis/methods , Food Contamination/analysis , Food Handling , Gas Chromatography-Mass Spectrometry/methods , Pesticide Residues/analysis
18.
Shokuhin Eiseigaku Zasshi ; 50(5): 243-52, 2009 Oct.
Article in Japanese | MEDLINE | ID: mdl-19897951

ABSTRACT

A rapid and simple multiresidue method has been established for determination of pesticide residues in processed foods by GC/MS/MS. The pesticides were extracted with ethyl acetate, and were cleaned up with a double-layered SPE cartridge column (graphite carbon black/PSA silica gel). Recovery tests of 258 pesticides from five kinds of processed foods (dumpling, curry, French fries, fried chicken, fried fish) were performed at two different fortification levels of 0.02 and 0.1 microg/g, and 184 pesticides showed acceptable recovery (70-120%) with relative standard deviation of

Subject(s)
Food Analysis/methods , Food Contamination/analysis , Food Handling , Gas Chromatography-Mass Spectrometry/methods , Pesticide Residues/analysis , Tandem Mass Spectrometry/methods
19.
Shokuhin Eiseigaku Zasshi ; 50(1): 10-5, 2009 Feb.
Article in Japanese | MEDLINE | ID: mdl-19325220

ABSTRACT

A rapid and easy multiresidue method for determination of pesticide residues in Chinese dumplings using liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed. Pesticide residues were extracted with ethyl acetate in the presence of anhydrous magnesium sulfate in a disposable tube using a homogenizer. The extract was concentrated and reconstituted in hexane, followed by acetonitrile-hexane partition to remove lipids. The acetonitrile layer was purified with a double-layered cartridge column (graphite carbon black/primary secondary amine silica gel). After removal of the solvent, the extract was resolved in methanol/water and analyzed with LC-MS/MS. Recovery tests of 99 pesticide residues from Chinese dumpling were performed at 20 and 100 ng/g, and 72 pesticides exhibited acceptable recoveries (70-120%) with low relative standard deviations (<20%) at both concentrations. The time for sample preparation with 12 samples to test solutions was approximately 6 hr. This method could be useful for determination of pesticide residues in the Chinese dumplings.


Subject(s)
Chromatography, Liquid/methods , Food Analysis/methods , Pesticide Residues/analysis , Tandem Mass Spectrometry/methods
20.
J AOAC Int ; 91(4): 871-83, 2008.
Article in English | MEDLINE | ID: mdl-18727548

ABSTRACT

The applicability of a rapid and easy multiresidue method for determination of pesticide residues in agricultural products by using liquid chromatography/tandem mass spectrometry (LC/MS/MS) was examined. Pesticide residues were extracted with acetonitrile in a disposable tube using a homogenizer, followed by salting out with anhydrous magnesium sulfate and sodium chloride. The extract was purified with a double-layered cartridge column (graphite carbon black/primary-secondary amine silica gel). After removal of the solvent, the extract was resolved in methanol-water and analyzed with LC/MS/MS. Recovery tests of 99 pesticide residues from 7 agricultural products were performed at 20 and 100 ng/g. Throughout all of the agricultural products tested, 47 pesticides exhibited satisfactory recoveries (70-120%) and relative standard deviations (<20%) at both concentrations. The time for processing of 12 samples to test solutions was approximately 2-3 h. This method could be useful for determination of pesticide residues in agricultural products.


Subject(s)
Edible Grain/chemistry , Fruit/chemistry , Pesticide Residues/analysis , Vegetables/chemistry , Chromatography, Liquid , Computer Simulation , Indicators and Reagents , Legislation, Food , Phenyl Ethers , Propionates/chemistry , Reproducibility of Results , Tandem Mass Spectrometry
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