Evaluation of a Fluorodensitometric Method for Analysis of Ergosterol as a Fungal Marker in Compound Feeds

1999 ◽  
Vol 62 (6) ◽  
pp. 686-690 ◽  
Author(s):  
J. D. BAILLY ◽  
P. LE BARS ◽  
A. PIETRI ◽  
G. BENARD ◽  
J. LE BARS
Keyword(s):  
Essential Role ◽  
Limit Of Detection ◽  
Fungal Contamination ◽  
Good Marker ◽  
Storage Fungi ◽  
Quantitative Development ◽  
Tlc Plates ◽  
Mixed Feeds ◽  
Layer Chromatography ◽  
Tlc Separation

Ergosterol is the principal sterol of fungi and plays an essential role as a component of the cell membrane and other cell constituents. This molecule is considered a good marker of fungal contamination in foods and feeds. This paper reports a rapid and sensitive method to test ergosterol content in compound feeds based on fluorodensitometry after thin-layer chromatography (TLC) separation. This method involves a thermal treatment of TLC plates that leads to the formation of a highly fluorescent ergosterol derivative. Such a dosage allows ergosterol testing in any naturally contaminated samples (limit of detection: 1 ppm of ergosterol) and gives results in close agreement with high-pressure liquid chromatography determination. Moreover, values obtained on mixed feeds for animals at different steps of fungal contamination are linked to quantitative development of storage fungi, evaluated by mycological technique, reinforcing the interest of a rapid method for measuring this fungal marker.

Determination of Aflatoxins, Ochratoxin A, and Zearalenone in Mixed Feeds, with Detection by Thin Layer Chromatography or High Performance Liquid Chromatography

1981 ◽  
Vol 64 (6) ◽  
pp. 1356-1363 ◽  
Author(s):  
Mary V Howell ◽  
Philip W Taylor
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Wide Range ◽  
Mixed Feeds ◽  
Layer Chromatography

Abstract A sensitive, reliable, and economical method for the determination of 6 mycotoxins in mixed feeds is described. The feed is extracted with chloroform-water and the extract is cleaned up by using a disposable Sep-Pak silica cartridge. The procedure requires less time (15 min from sample extraction to extract preparation) and less solvent (approximately one-tenth) compared with conventional methods and is suitable for a fast, economical screen. Additional cleanup procedures, involving dialysis or extraction into base, are described for samples containing high levels of interfering compounds. Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) with fluorescence detection are described for identification and estimation of mycotoxins. The method has been applied to a wide range of mixed feeds, including laboratory animal diets, and raw materials. The limit of detection is 1 μg/kg for all mycotoxins measured by HPLC.

Thin Layer Chromatographic Determination of Aflatoxin B1 in Corn Silage

1978 ◽  
Vol 61 (6) ◽  
pp. 1363-1365
Author(s):  
Per E Häggblom ◽  
Howard H Casper
Keyword(s):  
Thin Layer ◽  
Aflatoxin B1 ◽  
Detection Method ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Early Spring ◽  
Corn Silage ◽  
Mixed Feeds ◽  
Layer Chromatography

Abstract A procedure is described for the purification and quantitation of aflatoxin B1 in corn silage. The toxin is extracted and partially purified using parts of the AOAC minicolumn detection method. The extract is further cleaned up on a 2-step minicolumn and is then analyzed by using thin layer chromatography. Essentially all interferences are removed when the procedure is applied to moldy and non-moldy corn silage. The estimated limit of detection is 5 μg aflatoxin B1/kg corn silage, and 73±8% of the added aflatoxin B1 (20 and 85 μg/kg) was recovered. No aflatoxin B1 was detected in 270 samples collected from 19 silage piles in late fall 1976 and early spring 1977. This procedure also removes interferences associated with moldy corn and mixed feeds.

scholarly journals Densitometric High Performance Thin-Layer Chromatography Identification and Quantitative Analysis of Psychotropic Drugs

2005 ◽  
Vol 88 (1) ◽  
pp. 70-79 ◽  
Author(s):  
Anna Maślanka ◽  
Jan Krzek
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Psychotropic Drugs ◽  
High Performance ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Experimental Conditions ◽  
Mobile Phases ◽  
Tlc Plates ◽  
Layer Chromatography

Abstract A thin-layer chromatography (TLC)-densitometry method has been developed to identify and quantify haloperidol, amitriptyline, sulpiride, promazine, fluphenazine, doxepin, diazepam, trifluoperazine, clonazepam, and chlorpromazine in selected psychotropic drugs. Separation was performed on precoated silica gel 60 F254 TLC plates. Chromatograms were developed in various mobile phases, and 8 of 30 tested phases were selected based on spot location and developing time. The identification and quantification were carried out based on ultraviolet densitometric measurements at chosen wavelengths. In addition to retention coefficients, the absorption spectra recorded directly from chromatograms were also used in qualitative analysis. Under established experimental conditions, high sensitivity of the method was achieved. The limit of detection ranged from 0.009 to 0.260 μg, depending on the wavelength selected for measuring. A satisfactory recovery, ranging from 92.99 to 104.70%, was achieved for individual constituents.

scholarly journals DETERMINATION OF 10-GINGEROL IN INDIAN GINGER BY VALIDATED HPTLC METHOD OF SAMPLES COLLECTED ACROSS SUBCONTINENT OF INDIA

2016 ◽  
Vol 8 (12) ◽  
pp. 190
Author(s):  
Kamran Ashraf ◽  
Syed Adnan Ali Shah ◽  
Mohd Mujeeb
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Aluminum Plates ◽  
Layer Chromatography ◽  
Hptlc Method

<p><strong>Objective: </strong>A simple, sensitive, precise, and accurate stability indicating HPTLC (high-performance thin-layer chromatography) method for analysis of 10-gingerol in ginger has been developed and validated as perICH guidelines.</p><p><strong>Methods: </strong>The separation was achieved on TLC (thin layer chromatography) aluminum plates pre-coated with silica gel 60F<sub>254</sub> using n-hexane: ethyl acetate 55:45 (%, v/v) as a mobile phase. Densitometric analysis was performed at 569 nm.</p><p><strong>Results: </strong>This system was found to have a compact spot of 10-gingerol at <em>R</em><sub>F</sub> value of 0.57±0.03. For the proposed procedure, linearity (<em>r</em><sup>2</sup> = 0.998±0.02), limit of detection (18ng/spot), limit of quantification (42 ng/spot), recovery (ranging from 98.35%–100.68%), were found to be satisfactory.</p><p><strong>Conclusion: </strong>Statistical analysis reveals that the content of 10-gingerol in different geographical region varied significantly. The highest and lowest concentration of 10-gingerol in ginger was found to be present in a sample of Patna, Lucknow and Surat respectively which inferred that the variety of ginger found in Patna, Lucknow are much superior to other regions of India.</p>

Mass spectrometry as a versatile ancillary technique for the rapid in situ identification of lichen metabolites directly from TLC plates

2017 ◽  
Vol 49 (5) ◽  
pp. 507-520 ◽  
Author(s):  
Pierre LE POGAM ◽  
Aline PILLOT ◽  
Françoise LOHEZIC-LE DEVEHAT ◽  
Anne-Cécile LE LAMER ◽  
Béatrice LEGOUIN ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Accurate Identification ◽  
Chemical Profiling ◽  
Analytical Strategies ◽  
Tlc Plates ◽  
Lichen Metabolites ◽  
Acetone Extracts ◽  
Layer Chromatography ◽  
Structural Classes

AbstractThin-layer chromatography (TLC) still enjoys widespread popularity among lichenologists as one of the fastest and simplest analytical strategies, today remaining the primary method of assessing the secondary product content of lichens. The pitfalls associated with this approach are well known as TLC leads to characterizing compounds by comparison with standards rather than properly identifying them, which might lead to erroneous assignments, accounting for the long-held interest in hyphenating TLC with dedicated identification tools. As such, commercially available TLC/Mass Spectrometry (MS) interfaces can be easily connected to any brand of mass spectrometer without adjustments. The spots of interest are extracted from the TLC plate to retrieve mass spectrometric signals within one minute, thereby ensuring accurate identification of the chromatographed substances. The results of this hyphenated strategy for lichens are presented here by 1) describing the TLC migration and direct MS analysis of single lichen metabolites of various structural classes, 2) highlighting it through the chemical profiling of crude acetone extracts of a set of lichens of known chemical composition, and finally 3) applying it to a lichen of unknown profile, Usnea trachycarpa.

Notizen: Improved 2,4-Dinitrophenylhydrazine, Thin Layer Chromatography Methods for the Determination of Micro- and Macroamounts of Ascorbic Acid

1974 ◽  
Vol 29 (11-12) ◽  
pp. 777-780 ◽  
Author(s):  
A. Navon ◽  
H. Z. Levinson
Keyword(s):  
Acetic Acid ◽  
Vitamin C ◽  
Thin Layer ◽  
Condensation Reaction ◽  
Dehydroascorbic Acid ◽  
Previous Method ◽  
Aqueous Acetic Acid ◽  
Tlc Plates ◽  
Layer Chromatography

Microamounts of vitamin C could be readily determined in 20 μl-samples using the 2,4-dinitrophenylhydrazine method together with separation by thin layer chromato­graphy. The condensation reaction was carried out for 5 min at 100 °C on a glass fibre disc. Purification of vitamin C hydrazones was accomplished by repeated separation on TLC plates. An aqueous solution of 65% acetic acid was em­ployed to dissolve the vitamin C hydrazones, providing maxi­mal absorbance at 500 nm. The minimum amount detectable by this method is 0.4 μg of dehydroascorbic acid. The macrodetermination of vitamin C was improved by simpli­fying a previous method and employing 65% aqueous acetic acid as a solvent for the hydrazones.

Rapid Thin Layer Chromatographic Determination of Aflatoxin M1 in Powdered Milk

1985 ◽  
Vol 68 (5) ◽  
pp. 952-954
Author(s):  
Maria Luisa Serralheiro ◽  
Maria Lurdes Quinta
Keyword(s):  
Aqueous Solution ◽  
Carbon Tetrachloride ◽  
Thin Layer ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Methanol Solution ◽  
Aflatoxin M1 ◽  
Powdered Milk ◽  
Layer Chromatography

Abstract A method has been developed for the detection of aflatoxin Mi in milk. The toxin is extracted with chloroform, the extract is evaporated, and the residue is partitioned between carbon tetrachloride and an aqueous saline-methanol solution. The toxin is once again extracted with chloroform from the methanol solution and analyzed by thin layer chromatography. The limit of detection of Mi in powdered milk is 0.5 μg/ kg; recoveries of added Mj are about 83%. The limit of detection can be improved to 0.3 μg/kg if the plate is sprayed with an aqueous solution of H2S04 after development.

Analysis of Dairy Products for Chlorinated Insecticide Residues by Thin Layer Chromatography

1966 ◽  
Vol 49 (4) ◽  
pp. 795-800
Author(s):  
William A Moats
Keyword(s):  
Aluminum Oxide ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Silica Gel ◽  
Color Development ◽  
Tlc Plates ◽  
One Step ◽  
Rf Values ◽  
Tlc Analysis ◽  
Layer Chromatography

Abstract Butterfat and milk samples were analyzed for chlorinated insecticides by thin layer chromatography (TLC) on aluminum oxide or silica gel plates containing a small amount of silver nitrate. The adsorbent was washed with distilled water before preparing the plates. A one-step cleanup on a partially inactivated Florisil column was performed prior to TLC analysis. For color development, the TLC plates were sprayed lightly with hydrogen peroxide to suppress possible interference from fat and then steamed before exposure to ultraviolet light to accelerate and intensify the color reaction. Rf values for a number of solvent systems on aluminum oxide and silica gel plates are given. With this procedure, 0.05 μg or less of insecticide can be detected in a 0.4 g butterfat sample or the extract from 10 ml milk.

Thin Layer Chromatographic Determination of Citrinin

1979 ◽  
Vol 62 (1) ◽  
pp. 201-202 ◽  
Author(s):  
Robert D Stubblefield
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Linear Relationship ◽  
Silica Gel ◽  
Coefficient Of Variation ◽  
Ethylenediaminetetraacetic Acid ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Tlc Plates

Abstract Clearly defined zones of citrinin can be obtained on thin layer chromatographic (TLC) plates and measured by fluorodensitometry. Silica gel plates were prepared as a slurry with aqueous 0.05M Na2EDTA (ethylenediaminetetraacetic acid), spread at 0.5 mm wet thickness, and activated at 105°C for 1 hr. Plates were developed in acetic acid-benzene (5+95). The limit of detection was 10 ng citrinin/zone. Densitometric analysis (365 nm excitation, 505 nm emission) revealed that a linear relationship exists for levels of 10 ng to at least 100 ng/zone wtih a coefficient of variation of ±5%.

scholarly journals Alkaloids of the sorghum ergot pathogen (Claviceps africana): assay methods for grain and feed and variation between sclerotia/sphacelia

2003 ◽  
Vol 54 (2) ◽  
pp. 167 ◽  
Author(s):  
B. J. Blaney ◽  
R. Maryam ◽  
S-A. Murray ◽  
M. J. Ryley
Keyword(s):  
High Performance ◽  
Ammonium Hydroxide ◽  
Alkaloid Content ◽  
Phase Detection ◽  
South Wales ◽  
Claviceps Africana ◽  
Assay Methods ◽  
Total Alkaloid Content ◽  
Mixed Feeds ◽  
Layer Chromatography

Assay methods for the alkaloids of sorghum ergot (Claviceps africana) are described and compared. Sorghum ergot bodies (sclerotia/sphacelia) from various regions of Queensland and New South Wales were collected in 1997 and 2001 and assayed by spectrophotometry, thin layer chromatography, or high performance liquid chromatography (HPLC). All contained dihydroergosine (DHES) as the main alkaloid component (about 80%), with smaller amounts of dihydroelymoclavine and festuclavine. The preferred method of assay for infected sorghum and mixed feeds involved extraction into dichloromethane:methanol:ethyl acetate:ammonium hydroxide (50:5:25:1) using an ultrasonic bath. After solvent removal, the extract was dissolved in diethyl ether and partitioned into 0.5 M hydrochloric acid. After adjusting the pH to 8–10 with ammonium hydroxide, the alkaloids were extracted into dichloromethane, the solvent evaporated, and the residue dissolved in methanol. HPLC separation was on a C18 column, 150 × 3.9 mm, run isocratically at 40�C, with acetonitrile:0.1% ammonium acetate:methanol (31:50:20) as the mobile phase. Detection was either by UV at 280 nm or by fluorescence with excitation at 235 nm and absorbance at 340 nm. Levels of quantitation for DHES in sorghum approached 0.1 mg/kg (UV) and 0.01 mg/kg (fluorescence). Method recoveries for DHES in the range of 0.025–7 mg/kg averaged 75%. The total alkaloid content of ergot bodies (sclerotia/sphacelia) from different batches of grain varied from 100 to 7900 mg/kg (0.79%). Within batches, there was much less variation in the alkaloid content of ergot bodies, but larger ergots tended to contain more alkaloid than smaller ergots, and those infected with Cerebella species contained even less; this probably related to the ratio of sclerotial/sphacelial tissue present. Honeydew also contained DHES (1–10 mg/kg) and might contaminate clean grain at significant levels. Tests on 4 farms showed that substantial amounts of ergot bodies and alkaloids were removed during grain harvesting.

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