Head Space Gas Procedure for Screening Food Samples for Dithiocarbamate Pesticide Residues

1969 ◽  
Vol 52 (6) ◽  
pp. 1226-1230 ◽  
Author(s):  
H A Mcleod ◽  
K A Mccully
Keyword(s):  
Pesticide Residues ◽  
Stannous Chloride ◽  
Food Samples ◽  
Screening Procedure ◽  
Head Space ◽  
The Difference ◽  
Celery Cabbage

Abstract screening procedure has been developed for dithiocarbamate residues in foods. The CS2 evolved from an H2SO4-sample mixture at 60°C for 30 min was determined by GLC; recoveries of ferbam, thiram, and ziram added to apples, strawberries, lettuce, celery, cabbage, cucumber, and carrots ranged from 80 to 114% at 3.5 ppm and from 86 to 112% at 7 ppm. Recoveries of maneb, nabam, and zineb were not satisfactory. When an HCl-stannous chloride reagent was substituted for the H2SO4 reagent, recoveries of the ethylenebisdithiocarbamates were considerably improved. Maneb and ziram recoveries ranged from 70 to 95% in all samples; ferbam, thiram, and ziram, from 84 to 100%; and nabam, from 44 to 83%. The difference between duplicate recovery values, using the latter reagent, ranged from 0 to 11.2% units; 87% of these values were less than 10%.

scholarly journals One-Step Chromatographic Cleanup of Chlorinated Hydrocarbon Pesticide Residues in Butterfat. II. Chromatography on Florisil

1963 ◽  
Vol 46 (2) ◽  
pp. 172-176 ◽  
Author(s):  
William A Moats
Keyword(s):  
Petroleum Ether ◽  
Paper Chromatography ◽  
Pesticide Residues ◽  
Dairy Products ◽  
Methylene Chloride ◽  
Screening Procedure ◽  
Total Chloride ◽  
Chlorinated Hydrocarbon ◽  
Insecticide Residues ◽  
One Step

Abstract The procedure for chromatography on Florisil was modified by using methylene chloride-petroleum ether mixtures to improve separation of insecticides from fat. Combined with paper chromatography, it provides a screening procedure for insecticide residues in dairy products that is comparable in speed and simplicity to total chloride methods but is of superior sensitivity.

Screening Procedure for Organothiophosphate Pesticide Residues on Fruits and Vegetables by Microcoulometric Gas Chromatography

1964 ◽  
Vol 47 (2) ◽  
pp. 289-292
Author(s):  
Richard C Nelson
Keyword(s):  
Gas Chromatography ◽  
Petroleum Ether ◽  
Pesticide Residues ◽  
Fruits And Vegetables ◽  
Methyl Parathion ◽  
Screening Procedure ◽  
Gas Chromatograph

Abstract The Mills-Onley-Gaither procedure for extraction and cleanup of chlorinated pesticide residues in fruits and vegetables was adapted for use in organothiophosphate residue screening. The acetonitrile extraction-petroleum ether shakeout was employed, and up to 5 g of sample was injected into a microcoulometric gas chromatograph with no further cleanup. The microplatinum cell, which titrates only sulfur, was used. Recoveries from “spiked” fruits and vegetables (average of 2—3 determinations) were: Systox, 33%; Delnav, 68%; Diazinon, 86%; Di-Syston, 85%; methyl parathion, 82%; parathion, 88%; malathion, 71%; ethion, 107%; Trithion, 94%; EPN, 78%. Satisfactory baselines were obtained on plums, peaches, cherries, grapes, carrots, lettuce, cabbage, cauliflower, asparagus, and celery. Standard parent compounds only were studied.

scholarly journals Pesticide Residues in Canned Foods, Fruits, and Vegetables: The Application of Supercritical Fluid Extraction and Chromatographic Techniques in the Analysis

2003 ◽  
Vol 3 ◽  
pp. 1314-1326 ◽  
Author(s):  
Mohamed H. EL-Saeid
Keyword(s):  
Supercritical Fluid Extraction ◽  
Supercritical Fluid ◽  
Pesticide Residues ◽  
Fruits And Vegetables ◽  
Cost Effective ◽  
Food Samples ◽  
Fluid Extraction ◽  
Consumer Safety ◽  
Canned Foods ◽  
Multiple Pesticide Residues

Multiple pesticide residues have been observed in some samples of canned foods, frozen vegetables, and fruit jam, which put the health of the consumers at risk of adverse effects. It is quite apparent that such a state of affairs calls for the need of more accurate, cost-effective, and rapid analytical techniques capable of detecting the minimum concentrations of the multiple pesticide residues. The aims of this paper were first, to determine the effectiveness of the use of Supercritical Fluid Extraction (SFE) and Supercritical Fluid Chromatography (SFC) techniques in the analysis of the levels of pesticide residues in canned foods, vegetables, and fruits; and second, to contribute to the promotion of consumer safety by excluding pesticide residue contamination from markets. Fifteen different types of imported canned and frozen fruits and vegetables samples obtained from the Houston local food markets were investigated. The major types of pesticides tested were pyrethroids, herbicides, fungicides, and carbamates.By using these techniques, the overall data showed 60.82% of the food samples had no detection of any pesticide residues under this investigation. On the other hand, 39.15% different food samples were contaminated by four different pyrethroid residues ± RSD% ranging from 0.03 ± 0.005 to 0.05 ± 0.03 ppm, of which most of the pyrethroid residues were detected in frozen vegetables and strawberry jam. Herbicide residues in test samples ranged from 0.03 ± 0.005 to 0.8 ± 0.01 ppm. Five different fungicides, ranging from 0.05 ± 0.02 to 0.8 ±0.1 ppm, were found in five different frozen vegetable samples. Carbamate residues were not detected in 60% of investigated food samples. It was concluded that SFE and SFC techniques were accurate, reliable, less time consuming, and cost effective in the analysis of imported canned foods, fruits, and vegetables and are recommended for the monitoring of pesticide contaminations.

Comparison of a Four-Section Spindle and Stomacher for Efficacy of Detaching Microorganisms from Fresh Vegetables

2015 ◽  
Vol 78 (7) ◽  
pp. 1380-1386 ◽  
Author(s):  
DO-KYUN KIM ◽  
SOO-JI KIM ◽  
DONG-HYUN KANG
Keyword(s):  
Foodborne Pathogens ◽  
Food Samples ◽  
Plate Count ◽  
Microbiological Analysis ◽  
Vegetable Samples ◽  
Fresh Vegetable ◽  
Detection Analysis ◽  
Fresh Vegetables ◽  
The Difference ◽  
Aerobic Plate Count

This study was undertaken to compare the effect of the spindle and stomacher for detaching microorganisms from fresh vegetables. The spindle is an apparatus for detaching microorganisms from food surfaces, which was developed in our laboratory. When processed with the spindle, food samples were barely disrupted, the original shape was maintained, and the diluent was clear, facilitating further detection analysis more easily than with stomacher treatment. The four-section spindle consists of four sample bag containers (A, B, C, and D) to economize time and effort by simultaneously processing four samples. The aerobic plate counts (APC) of 50 fresh vegetable samples were measured following spindle and stomacher treatment. Correlations between the two methods for each section of the spindle and stomacher were very high (R2 = 0.9828 [spindle compartment A; Sp A], 0.9855 [Sp B], 0.9848 [Sp C], and 0.9851 [Sp D]). One-tenth milliliter of foodborne pathogens suspensions was inoculated onto surfaces of food samples, and ratios of spindle-to-stomacher enumerations were close to 1.00 log CFU/g between every section of the spindle and stomacher. One of the greatest features of the spindle is that it can treat large-sized samples that exceed 200 g. Uncut whole apples, green peppers, potatoes, and tomatoes were processed by the spindle and by hand massaging by 2 min. Large-sized samples were also assayed for aerobic plate count and recovery of the three foodborne pathogens, and the difference between each section of the spindle and hand massaging was not significant (P > 0.05). This study demonstrated that the spindle apparatus can be an alternative device for detaching microorganisms from all fresh vegetable samples for microbiological analysis by the food processing industry.

scholarly journals Domestic Gardens Mitigate Risk of Exposure of Pollinators to Pesticides—An Urban-Rural Case Study Using a Red Mason Bee Species for Biomonitoring

2020 ◽  
Vol 12 (22) ◽  
pp. 9427
Author(s):  
Martin Šlachta ◽  
Tomáš Erban ◽  
Alena Votavová ◽  
Tomáš Bešta ◽  
Michal Skalský ◽  
...  
Keyword(s):  
Pesticide Residues ◽  
Fruit Trees ◽  
Osmia Bicornis ◽  
Domestic Gardens ◽  
Urban Rural ◽  
Risk Of Exposure ◽  
The Difference ◽  
Fruit Orchards

Domestic gardens supply pollinators with valuable habitats, but the risk of exposure to pesticides has been little investigated. Artificial nesting shelters of a red mason bee species (Osmia bicornis) were placed in two suburban gardens and two commercial fruit orchards to determine the contamination of forage sources by pesticides. Larval pollen provisions were collected from a total of 14 nests. They consisted mainly of pollen from oaks (65–100% weight/sample), Brassicaceae (≤34% w/s) and fruit trees (≤1.6% w/s). Overall, 30 pesticides were detected and each sample contained a mixture of 11–21 pesticide residues. The pesticide residues were significantly lower in garden samples than in orchard samples. The difference was attributed mainly to the abundant fungicides pyrimethanil and boscalid, which were sprayed in fruit orchards and were present on average at 1004 ppb and 648 ppb in orchard samples, respectively. The results suggested that pollinators can benefit from domestic gardens by foraging from floral sources less contaminated by pesticides than in adjacent croplands.

scholarly journals APPLICATION OF THE IMPEDANCE METHOD FOR DETERMINATION OF MONOSODIUM GLUTAMATE IN FOOD PRODUCTS

2020 ◽  
Vol 14 (2) ◽  
Author(s):  
Yu. Slyva ◽  
E. Pokhodylo
Keyword(s):  
Monosodium Glutamate ◽  
Impedance Analysis ◽  
Food Samples ◽  
Impedance Method ◽  
Food Fraud ◽  
Reactive Component ◽  
Mashed Potatoes ◽  
The Difference ◽  
Control Samples

The article presents the results of studying how impedance analysis can be used for determination of monosodium glutamate in order to identify food fraud. We have suggested that the parameters of complex conductivity (admittance) of a two-terminal circuit could allow detecting monosodium glutamate (E 621), an additive used in the food industry to enrich the taste. The method involves passing current of different frequencies through solid foodstuffs and a cell with liquid foodstuffs, measuring the electrical conductivity, and determining and analysing the frequency dependence of admittance. The active G component and the reactive B component of the admittance have been measured at different frequencies, from 100 Hz to 100 kHz. For the experiment, food samples were prepared in accordance with the Codex Alimentarius recommendations for the dosage of the food additive E 621: orange juice with monosodium glutamate added in the amount of 0.3%, and mashed potatoes with glutamate added in the amount of 1%, of the total weight of the products. The temperature of the tested products was 22 ± 0.2°С. The results of the studies have shown the dependences of the admittance components on the frequency for the control samples of juice and mashed potatoes and for the samples with monosodium glutamate added. The dependence of the active component and the reactive component of the foodstuff admittance have been established, with monosodium glutamate (added in the above-specified proportion) and without it. The difference is in how the dependences change in their nature. The monosodium glutamate curves both in juice and in mashed potatoes are similar. The samples containing monosodium glutamate have far higher values of the active and reactive admittance component than the control samples do, with a distinct peak of the reactive component characteristic. Therefore, impedance analysis is a possible method to detect quickly the flavour enhancer monosodium glutamate in foods of different consistency and thus identify food fraud.

Sign in / Sign up

Export Citation Format

Share Document