Residual behavior and dietary risk assessment of albendazole as fungicide in citrus orchards

Albendazole is a broad-spectrum fungicide that shows great potential in controlling fungal diseases in citrus. To quantify the dissipation behavior, residue distribution, and dietary risk of albendazole in citrus, we developed an UPLC-MS/MS analysis protocol. The average recovery rate of albendazole in whole citrus and citrus pulp ranged from 74 to 105% with an RSD of 3 to 8%, and a limit of quantification of 0.01 mg kg^-1. The degradation half-lives were 2.8-3.0 and 5.7-17.0 days in whole citrus and citrus pulp, respectively, and the final residues of albendazole were <0.059 mg kg^-1 with a risk quotient of <1. This study not only demonstrates that the dietary risk of albendazole in citrus is negligible, but also provides empirical data to establish the maximum residual limit (MRL) for the safe application of albendazole in citrus orchards to meet the requirements for food safety as well as international trade.

Highly sensitive electro-oxidative voltammetric determination of anthelmintic drug albendazole using porous graphitic carbon nitride sensor infused with cationic micellar solution

A sensitive and novel electrochemical senser, acetyl trimethylammonium bromide (CTAB)-immobilized nitrogen rich g-C₃N₄ nanosheet modified carbon paste electrode was developed, for the electrochemical investigation of the anthelmintic drug Albendazole (ABZ) using voltammetric tools like cyclic and square wave voltammetry. The results showed that the modified carbon paste electrode exhibited remarkable electro-catalytic action towards the electrochemical oxidation of ABZ in a phosphate buffer solution at pH 3 compared to bare carbon paste electrode. The electrode material was characterized by CV, scanning electron microscopy (SEM), atomic force microscope (AFM), and electrochemical impedance spectroscopy (EIS). A highly sensitive square wave voltammetric technique was developed for the determination of ABZ, at a trace level with great precision and accuracy, good limit of detection (LOD) 0.01 µM and limit of quantification (LOQ) of 0.036 µM, in the concentration range of 0.2-10 µM. This approach can be used in pharmaceutical formulations for clinical diagnosis, quality assurance, and drug screening. In addition, this technique is also implemented for the assessment of ABZ in water samples and biological samples like urine and blood plasma.

Simple and rapid spectrophotometric assay of albendazole in pharmaceuticals using iodine and picric acid as CT complexing agents

Two simple, rapid and inexpensive spectrophotometric methods are described for the determination of albendazole (ALB) in bulk drug and in tablets. The methods are based on charge-transfer (CT) complexation reaction involving ALB as n-donor and iodine as σ-acceptor (method A) in dichloromethane or picric acid (PA) as π-acceptor (method B) in chloroform. The absorbance of CT complexes was measured at 380 nm for method A, and 415 nm for method B. The optimization of the experimental conditions is described. Under optimum conditions, Beer's law obeyed over the concentration ranges 8.0-240 and 2.4-42 μg mL-1 for method A and method B, respectively. The apparent molar absorptivity of CT complexes at the respective λmax are calculated to be 1.17×103 and 5.22×103 L mol-1cm-1 respectively, and the corresponding Sandell sensitivity values are 0.2273 and 0.0509 ng cm-2. The limits of detection (LOD) and quantification (LOQ) are calculated to be (0.69 and 2.08), and (0.10 and 0.30) μg mL-1 with method A, and method B, respectively. The intra-day and inter-day accuracy expressed as % RE and precision expressed as % RSD were less than 3%. The methods were applied to the determination of ALB in tablets.

Use of Two Sulfonphthalein Dyes for the Sensitive and Selective Extraction-Free Spectrophotometric Assay of Albendazole in Bulk Drug and in Tablets

Albendazole (ALB) is a potent benzimidazole anthelmintic used in the treatment of human intestinal helmintiasis as well as of hytatid cysts and neurocysticercosis. Two rapid, simple, sensitive, and selective spectrophotometric methods are presented for the determination of ALB in pharmaceuticals. The methods are based on the formation of dichloromethane soluble 1 : 1 ion-pair complexes (ALB : dye) formed between ALB and sulfonphthalein dyes, bromophenol blue BPB, (method A) and bromothymol blue BTB, (method B). The complexes formed were measured directly (without extraction) at 445 nm (method A) and 460 nm (method B). The experimental conditions were optimized and the systems obey Beer’s law for 1.5–21.0 and 2.0–32.0 μg mL−1 ALB for method A and method B respectively. The molar absorptivity and Sandell's sensitivity were calculated to be  L mol−1 cm−1 and 0.0209 ng cm−2, and  L mol−1 cm−1 and 0.0350 ng cm−2 using BPB and BTB, respectively. The limits of detection and quantification were calculated to be 0.01 and 0.03, and 0.16, and 0.49 μg mL−1 using BPB and BTB, respectively. The relative standard values for intra-day and inter-day precision were less than 3%, and the accuracy was better than 3% for both methods.