scholarly journals Dissipation and Residues of Mandipropamid in Grape Using QuEChERS Methodology and HPLC-DAD

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Farag M. Malhat ◽  
Hend A. Mahmoud
Keyword(s):  
Analytical Method ◽  
Pesticide Residues ◽  
Half Life ◽  
Hplc Method ◽  
Maximum Residue Limit ◽  
Quechers Method ◽  
Pesticide Application ◽  
The Mean ◽  
Preharvest Interval

The HPLC method for determination of mandipropamid residues and its dissipation in grape was investigated. The mean recoveries of the analytical method were 98–102%. The samples were collected within 2 weeks after pesticide application, and the pesticide residues were extracted by an optimized QuEChERS method. Mandipropamid dissipated rapidly with half-life 2.20 days in grape. According to maximum residue limit (MRL) the preharvest interval (PHI) of mandipropamid on grape was 4 days, after the last treatment.

Determination of Residues of Diazinon and Chlorpyrifos in Lavender and Rosemary Leaves by Gas Chromatography

2018 ◽  
Vol 101 (2) ◽  
pp. 587-592 ◽  
Author(s):  
Mamdouh R Rezk ◽  
Abd El-Aziz B Abd El-Aleem ◽  
Shaban M Khalile ◽  
Omneya K El-Naggar
Keyword(s):  
Gas Chromatography ◽  
Ethyl Acetate ◽  
Sodium Sulfate ◽  
Half Life ◽  
Capillary Gc ◽  
Pesticide Application ◽  
Rotary Evaporator ◽  
Life Values ◽  
Preharvest Interval

Abstract A sensitive gas chromatographic (GC) GC method has been developed for the determination of diazinon and chlorpyrifos residues in lavender and rosemary leaves. The developed method consists of blending weighed samples of chopped leaves with sodium sulfate as the dehydrating agent, extraction with ethyl acetate, filtration, evaporation with a rotary evaporator, and, finally, capillary GC determination of the pesticides. The recoveries of the method were greater than 90%, and the LOQ was less than 0.1 µg/mL. The method was applied to determine the rate of disappearance of diazinon and chlorpyrifos from lavender and rosemary leaves pretreated with the studied pesticides. The half-life values (t1/2) of diazinon were found to be 5.93 and 6.35 days for lavender and rosemary leaves, respectively, whereas the t1/2 values of chlorpyrifos were calculated to be 7.86 and 9.52 days for lavender and rosemary leaves, respectively. The safe harvest interval (preharvest interval; PHI) was suggested to be after 21 and 24 days for diazinon and chlorpyrifos, respectively. The PHI refers to the amount of time that must lapse (in days) after a pesticide application before a crop can be cut.

Development and Validation of an HPLC Method for Determination of Spirotetramat and Spirotetramat cis enol in Various Vegetables and Soil

2013 ◽  
Vol 96 (3) ◽  
pp. 670-675 ◽  
Author(s):  
Balwinder Singh ◽  
Kousik Mandal ◽  
Sanjay K Sahoo ◽  
Urvashi Bhardwaj ◽  
Raminderjit Singh Battu
Keyword(s):  
Analytical Method ◽  
Anhydrous Sodium Sulfate ◽  
Hplc Method ◽  
Array Detector ◽  
Photodiode Array Detector ◽  
Photodiode Array ◽  
Precision And Accuracy ◽  
Hplc Grade Acetonitrile ◽  
Development And Validation

Abstract An easy and simple analytical method was standardized and validated for the estimation of residues of spirotetramat and its metabolite spirotetramat cis enol in various substrates: okra fruits, brinjal leaves and fruits, green chili, red chili, and soil. The samples were extracted with acetonitrile, diluted with brine solution, partitioned into dichloromethane, dried over anhydrous sodium sulfate, and cleaned up by treatment with activated charcoal powder. Final clear extracts were concentrated under vacuum and reconstituted with HPLC grade acetonitrile. Residues were estimated using HPLC with a photodiode array detector and a C18 column, and confirmed by HPTLC. Acetonitrile was used as the mobile phase at 0.4 mL/min. Both spirotetramat and spirotetramat cis enol presented distinct peak at retention times of 8.518 and 7.598 min, respectively. Consistent recoveries ranging from 82 to 97% for spirotetramat and spirotetramat cis enol were observed when samples were spiked at 1.00 to 0.03 mg/kg levels. The LOQ of the method was found to be 0.03 mg/kg. The analytical method was validated in terms of parameters, including selectivity, linearity, precision, and accuracy.

Analytical method for the determination of curcumin entrapped in polymeric micellar powder using HPLC

2021 ◽  
Vol 32 (4) ◽  
pp. 867-873
Author(s):  
Helmy Yusuf ◽  
Nina Wijiani ◽  
Rizka Arifa Rahmawati ◽  
Riesta Primaharinastiti ◽  
M. Agus Syamsur Rijal ◽  
...  
Keyword(s):  
Flow Rate ◽  
Analytical Method ◽  
Hplc Method ◽  
Array Detector ◽  
Good Resolution ◽  
Diode Array Detector ◽  
Accuracy And Precision ◽  
The Family ◽  
Effective Analysis

Abstract Objectives Curcumin belongs to the family of curcuminoids, natural polyphenolic compounds that possesses neuroprotective properties, anti inflammatory and anticancer. Its entrapment in the developed casein-based micellar powder (CMP) and poloxamer-based micellar powder (PMP) was to enhance the solubility and improve the bioavailability. Henceforth, the present study aimed to acquire an efficient analytical method for the curcumin analysis in polymeric micellar formulations. Methods A fast and specific HPLC method was developed for analyzing curcumin in two different micellar matrices using casein and poloxamer. The HPLC was equipped with a C18 column (250 × 4 mm, 5 µm) and diode array detector. A designated isocratic elution of curcumin was employed using mobile phase with a composition of water (1%, v/v acetic acid) and acetonitrile in a ratio of 50:50 v/v. The employed flow rate was 1.0 mL/min and the analyte was examined at 421 nm. Results An effective analysis in HPLC was successfully achieved by the predetermined HPLC condition. A good resolution of peaks at the employed flow rate was achieved. The linearity was excellent in two different range of concentrations, 2–20 and 10–50 μg/mL. The selectivity, accuracy and precision fulfilled the acceptable requirements. Conclusions The developed method was practically effective to qualitatively identified curcumin. In addition, the assay also effectively quantified the amount of curcumin in the polymeric entrapping matrices which demonstrates that it has great potential to be used in natural compound analysis.

scholarly journals DEVELOPMENT AND VALIDATION OF BIOANALYTICAL HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF CILNIDIPINE AND NEBIVOLOL IN HUMAN PLASMA

2017 ◽  
Vol 9 (10) ◽  
pp. 253
Author(s):  
Aruna G. ◽  
Bharathi K ◽  
Kvsrg Prasad
Keyword(s):  
Human Plasma ◽  
Analytical Method ◽  
Internal Standard ◽  
Hplc Method ◽  
Pharmacokinetic Parameters ◽  
Simultaneous Estimation ◽  
Time Data ◽  
Bioanalytical Method Validation ◽  
Limit Of Quantitation ◽  
The Mean

Objective: To develop and validate a modified isocratic reversed-phase high performance liquid chromatographic (RP-HPLC) method for determination of cilnidipine and nebivolol in human plasma to be used for pharmacokinetic studies.Methods: The drug was extracted from plasma samples by direct protein precipitation technique using acetonitrile. Amlodipine was used as internal standard (IS). Samples were analyzed on BDS C18 column (250 x 4.6 mm, 5 µm), applying ortho phosphoric acid (0.1%): Acetonitrile, at a ratio of 45:55 v/v in isocratic mode as a mobile phase at a flow rate of 1 ml/min to attain adequate resolution. Separations were performed at room temperature and monitored at a wavelength of 260 nm after injection of 50μl samples into the HPLC system. The analytical method was validated according to FDA bioanalytical method validation guidance. The method was applied for pharmacokinetic study of cilnidipine and nebivolol tablets-10 mg and 5 mg were administered as a single dose to 6 healthy male rabbits under fasting condition. Twelve blood samples were withdrawn from each rabbit over 24 h periods. From the plasma concentration-time data of each individual, the pharmacokinetic parameters; Cmax, Tmax, AUC0-t and AUC0-∞ were calculated.Results: A peak area was obtained for cilnidipine and nebivolol at 3.943 and 4.719 min retention time respectively. Linearity was established at a concentration range of 0.20-20 μg/ml (r2=0.999, n=8) for cilnidipine and 0.02-2 μg/ml (r2=0.999, n=8) for nebivolol. The lower limit of quantitation (LLOQ) was identifiable and reproducible at 0.2μg/ml for cilnidipine and 0.02 μg/ml for nebivolol. The coefficients of variation (%cv) of the intra-day and inter-day precision of cilnidipine at 600, 1000 and 1600ng/ml levels were found to be 6.90%, 6.19%, 5.22%; and 7.74%, 6.54%, 5.77%, respectively, which are lower than the accepted criteria limits (15-20 %). The mean recovery (%) cilnidipine at 600, 1000, and 1600ng/ml was found to be 101.03%, 99.27% and 104.87%, and for nebivolol 60, 100, and 160 ng/ml was found to be 106.13%, 107.03% and 98.06% respectively. Stability at different conditions and in autosampler was also established. The mean pharmacokinetic parameters; Cmax, Tmax, AUC0-t and AUC0-∞ were 6 ng/ml, 2 hr, 96.76 mg. hr/ml, 63.45 mg. hr/ml for cilnidipine and 5.8ng/ml, 2hr, 74.78 mg. hr/ml, 100.25 mg. hr/ml for nebivolol respectively.Conclusion: The present analytical method was found to be specific, sensitive, accurate and precise for quantification of cilnidipine and nebivolol in human plasma. It can be successively applied for pharmacokinetics, bioavailability and bioequivalence studies.

scholarly journals Determination of Pesticide Residues in Honey by Single-Drop Microextraction and Gas Chromatography

2011 ◽  
Vol 94 (2) ◽  
pp. 634-644 ◽  
Author(s):  
Nikolaos G Tsiropoulos ◽  
Elpiniki G Amvrazi
Keyword(s):  
Pesticide Residues ◽  
Enrichment Factors ◽  
The European Union ◽  
Maximum Residue Limit ◽  
Single Drop ◽  
Limit Values ◽  
Screening Design ◽  
Single Drop Microextraction ◽  
Central Composite

Abstract A novel, simple, and rapid single-drop microextraction (SDME) procedure combined with GC has been developed, validated, and applied for the determination of multiclass pesticide residues in honey samples. The SDME was optimized using a Plackett-Burman screening design considering all parameters that may influence an SDME procedure and a consequent central composite design to control the parameters that were found to significantly influence the pesticide determination. The developed analytical method required minimal volumes of organic solvents and exhibited good analytical characteristics with enrichment factors ranging from 3 for -endosulfan to 10 for lindane, procymidone, and captan and method quantification limits ranging from 0.03 g/kg for phosalone to 10.6 g/kg for diazinon. The relative recoveries obtained ranged from 70.8 for captan to 120 for fenarimol, and the precision (RSD) ranged from 3 to 15. The proposed SDME procedure followed by GC with an electron capture detector for quantification and GC/MS for identification was applied with success to the analysis of 17 honey samples. Monitoring results indicated a low level of honey contamination by diazinon, chlorpyrifosethyl, procymidone, bromopropylate, and endosulfan (-, -, and endosulfan sulfate) residues that were far below the maximum residue limit values specified by the European Union for endosulfan (10 g/kg) and bromopropylate (100 g/kg) in honey samples.

scholarly journals Simultaneous HPLC Determination of Three Bioactive Alkaloids in the Asian Medicinal Plant Stephania rotunda

2010 ◽  
Vol 5 (6) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Sothavireak Bory ◽  
Sok-Siya Bun ◽  
Béatrice Baghdikian ◽  
Fathi Mabrouki ◽  
Sun Kaing Cheng ◽  
...  
Keyword(s):  
High Performance ◽  
Potassium Phosphate ◽  
Solvent System ◽  
Hplc Method ◽  
Photodiode Array Detection ◽  
Linear Behavior ◽  
Photodiode Array ◽  
Array Detection ◽  
The Mean

A reliable high-performance liquid chromatography (HPLC) method coupled with photodiode array detection has been developed and validated for the determination of three major alkaloids: cepharanthine, tetrahydropalmatine and xylopinine in Stephania rotunda Lour. (Menispermaceae) collected in Cambodia. The chromatographic separation was carried out on a Symmetry C8 column (250 mm x 4.6 mm, 5 μm, Waters), with an isocratic solvent system of 25 mM potassium phosphate buffer (pH 3.5) – acetonitrile. UV detection was performed at 282 nm. Good linear behavior over the investigated concentration ranges was observed with values of r2>0.9964 for all the analytes. The method was reproducible with intra- and inter-day variations of less than 3.91%. The mean recoveries of the analytes ranged from 95.7 to 104.6%. The proposed method was linear, accurate, precise and specific. The validated method was successfully applied to quantify the three alkaloids in various parts of Stephania rotunda and in tubers collected from different Cambodian regions. The results indicated that the developed HPLC method could be used for the quality control of S. rotunda.

Simple Analytical Method for Organophosphorus Pesticide Residues in Milk

1990 ◽  
Vol 73 (5) ◽  
pp. 770-772
Author(s):  
Masatake Toyoda ◽  
Kazuhiko Adachi ◽  
Tadakazu Ida ◽  
Katsuhiko Noda ◽  
Norio Minagawa
Keyword(s):  
Pesticide Residues ◽  
Milk Fat ◽  
Capillary Column ◽  
Organophosphorus Pesticide ◽  
Simple Method ◽  
Coefficients Of Variation ◽  
Complete Study ◽  
The Mean ◽  
Capillary Column Gas Chromatography

Abstract A simple method for determination of organophosphorus pesticide residues at the parts per million level In milk was developed. Pesticide residues were extracted with acetonitrlle added to aqueous milk, fat was removed by zinc acetate addition and dichloromethane partition, and analytes were concentrated and analyzed by wide-bore capillary column gas chromatography. Recoveries of 6 pesticides spiked in milk samples at levels of 0.1 and 1.0 μg/mL were 82.1- 93.8% and 79.7-96.6%, respectively. Triplicate samples spiked with 6 pesticides at 1 itg/mL were analyzed independently by 3 laboratories. Average recoveries were greater than 80%, and the mean coefficients of variation for the complete study were 2.9% for diazlnon, 5.4% for dimethoate, 4.6% for malathlon, 4.6% for parathlon, 4.9% for EPN, and 6.1% for phosalone.

Optimization of Sweep Codistillation Apparatus for Determination of Coumaphos and Other Organophosphorus Pesticide Residues in Animal Fat

1987 ◽  
Vol 70 (3) ◽  
pp. 442-445
Author(s):  
Robert L Brown ◽  
Clinton N Farmer ◽  
Roderick G Millar
Keyword(s):  
Coefficient Of Variation ◽  
Pesticide Residues ◽  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
Optimum Conditions ◽  
Animal Fat ◽  
Sweep Time ◽  
Coefficients Of Variation ◽  
The Mean

Abstract Optimum conditions have been developed for the quantitative recovery of coumaphos from animal fat by using a commercial sweep codistillation unit. Under the conditions specified (255°C distillation temperature, 250 mL/min of nitrogen, 60 min sweep time) and using Florisil trapping, the mean recovery of coumaphos was 91% with a coefficient of variation of 6%. Other organophosphorus pesticides recovered include diazinon, chlorpyrifos, ethion, and bromophos-ethyl with recoveries ranging from 90 to 96% and coefficients of variation ranging between 4 and 6%.

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