TWO WELL-KNOWN MICROEXTRACTION METHODS, DISPERSIVE LIQUID–LIQUID MICROEXTRACTION (DLLME) AND SOLID–PHASE MICROEXTRACTION (SPME), WERE COMBINED, RESULTING IN AS AN ENCOURAGING METHOD. THE METHOD, NAMED DLLME–SPME, WAS PERFORMED BASED ON TOTAL VAPORIZATION TECHNIQUE [1]. ....

HYDROCHLOROTHIAZIDE (HCTZ) IS A THIAZIDE DIURETIC AND ANTIHYPERTENSIVE DRUG USED IN THE TREATMENT OF OEDEMA ASSOCIATED WITH CONJESTIVE HEART FAILURE AND RENAL AND HEPATIC DISORDERS [1]. THE AIM OF THE PRESENT INVESTIGATIONS IS TO INTRODUCE LIQUID-LIQUID MICROEXTRACTION WITH HOLLOW FIBERS (HF-LPME) IN HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC) HAS BEEN APPLIED AS A NEW, FAST, SIMPLE AND EFFICIENT PROCEDURE FOR THE DETERMINATION OF HCTZ IN HUMAN URINE SAMPLE. THE TARGET COMPOUNDS WERE EXTRACTED FROM 24-ML AQUEOUS SAMPLE (DONOR SOLUTION, PH 12.0) THROUGH A MICROFILM OF ORGANIC SOLVENT (1-OCTANOL), IMMOBILIZED IN THE PORES OF A HOLLOW FIBER WITH 8.4 CM LENGTH FIXED ONTO THE TIP OF THE SYRINGE NEEDLE, WHICH WAS DIRECTLY IMMERSED INTO THE SAMPLE [2]. AFTER A PRESCRIBED PERIOD OF TIME, THE ACCEPTOR SOLUTION INSIDE THE FIBER WAS WITHDRAWN INTO THE MICROSYRINGE AND DIRECTLY INJECTED INTO THE HPLC SYSTEM FOR ANALYSIS. FACTORS RELEVANT TO THE EXTRACTION PROCEDURE WERE STUDIED: CHOOSING THE SUITABLE EXTRACTION SOLVENT, PH VALUE OF THE SAMPLE SOLUTION, THE EFFECT OF IONIC STRENGTH (WHICH FOUND THAT THE CONCENTRATION OF NACL SLIGHTLY DECREASES THE EXTRACTION EFFICIENCY), THE STUDY OF ION PAIR EFFECT (ALIQUAT-336 ADDED INTO THE EXTRACTION SOLVENT) [3], IT SHOWED THAT THE SIGNAL OF THE ANALYTE WAS INCREASED BY INCREASING THE CONCENTRATION OF ALIQUAT-336 UP TO 2% (V/V). THE STIRRING OF 800 RPM AND THE EXTRACTION TIME OF 90 MIN WERE CHOSEN AS THE OPTIMUM CONDITIONS.QUANTITATIVE PARAMETERS UNDER THE OPTIMIZED CONDITIONS WERE CALCULATED. LDR OVER THE RANGE OF 1.0-100MG L-1 OF HCTZ, R2 0.9933, LOD 0.5MG L-1, RSD% FOR FOUR REPLICATE MEASUREMENTS OF 25.0MG L-1 WAS 7.4%. UP TO 126-FOLD ENRICHMENT OF ANALYTES WAS DEFINED. IN ORDER TO ASSAY THE APPLICABILITY OF THE NEWLY DEVELOPED EXTRACTION SYSTEM, TAP WATER AND URINE SAMPLES WERE EXTRACTED AND ANALYZED AND MORE THAN 85% RELATIVE RECOVERY OF THE ANALYTE IN URINE SAMPLE WAS ACHIEVED. THE PRESENT STUDY EXHIBITED EXCELLENT PERFORMANCE OF THE CARRIER BASED HF-LPME TECHNIQUE FOR THE ANALYSIS AND EXTRACTION OF TRACE LEVELS OF HCTZ. THE PROPOSED METHOD PROVIDED HIGH PFS FOR THE TARGET ANALYTE, ALONG WITH AN EXCELLENT CLEAN-UP CAPABILITY. THE WHOLE OPERATION IS VERY CONVENIENT TO HANDLE BECAUSE THE RECEIVING PHASE IS PROTECTED BY THE HOLLOW FIBER.

MEFENAMIC ACID BELONGS TO THE ANTHRANILIC ACID DERIVATIVE CLASS OF NSAIDS (FENAMATES).MEFENAMIC ACID IS A CYCLO-OXYGENASE INHIBITOR AND BLOCKS THE PRODUCTION OF INTRACELLULAR PROSTAGLANDINS THAT ARE IMPORTANT IN PAIN AND INFLAMMATORY PATHWAYS. ...

BACKGROUND AND OBJECTIVE(S): IN RECENT YEARS, SYNTHETIC DYES ARE EXTENSIVELY USED IN VARIOUS INDUSTRIES. RHODAMINE B (RB); THEY BELONG TO THE CLASS OF SYNTHETICALLY XANTHINE DYES THAT ARE TOXIC AND CARCINOGENIC FOR HUMANS AND ANIMALS AND ARE PROHIBITED AGAINST FOODSTUFFS ALL OVER THE WORLD. IN THIS STUDY, AN EFFICIENT PRE-CONCENTRATION TECHNIQUE WAS DEVELOPED FOR THE DETERMINATION OF TRACE AMOUNTS OF RB FROM AQUEOUS SAMPLES. ...

THIS RESEARCH WAS INCLUDED COMBINATION SOLID PHASE EXTRACTION (SPE) TO DISPERSIVE LIQUID–LIQUID MICROEXTRACTION (DLLME) TO PRECONCENTRATION OF CU2+ IN VARIOUS SAMPLES. FOR THIS PURPOSE, THE RESULTANT OF SPE NEUTRALIZATION WAS USED AS SAMPLE SOLUTION IN DLLME PROCEDURE. N, N′-BIS (SALICYLIDEN) 2, 2-DIMETYL PROPAN-1, 3-DIAMINE (SMPA) IN ACETONE (AS DISPERSER SOLVENT) WITH ION LIQUID 1-HEXYL, 3-METHYL IMIDAZOLIUM HEXAFLUOROPHOSPHATE ([HMIM] PF6) (AS EXTRACTION SOLVENT) WERE USED. ALSO THE INFLUENCE OF SEVERAL PARAMETERS SUCH AS PH, LIGAND CONCENTRATION, AMOUNT OF DISPERSER SOLVENT, TYPE AND VOLUME OF EXTRACTION SOLVENT, EXTRACTION TIME, CENTRIFUGATION SPEED AND SALT EFFECT WAS EVALUATED AND OPTIMIZED. EFFECT OF INTERFERENCE IONS WAS INVESTIGATED. LIMITS OF DETECTION (LOD) AND RELATIVE STANDARD DEVIATION (RSD%) WERE (0.08MG L-1) AND (2.1 %), RESPECTIVELY.PRECONCENTRATION FACTOR OF THIS METHOD WAS 2500. COMBINATION OF SPE WITH DLLME WAS APPLIED TO THE EXTRACTION AND PRECONCENTRATION OF CU2+ IN NATURAL SAMPLES WITH HIGH RECOVERIES.

A SWITCHABLE-HYDROPHILICITY SOLVENT IN COMBINATION WITH AIR-ASSISTED LIQUID–LIQUID MICROEXTRACTION (AALLME) CALLED AA-SHS-LPME, HAS BEEN APPLIED FOR MICROEXTRACTION PALLADIUM...

IN THIS WORK CETYLTRIMETHYL AMMONIUM BROMIDE (CTAB) -COATED FE3O4@DECANOIC ACID WAS SYNTHESIZED AS AN EFFICIENT SORBENT FOR COEXTRACTION OF HYDROPHOBIC AND HYDROPHILIC DRUGS. TO ACHIEVE HIGH PRECONCENTRATION FACTORS (PFS), EFFICIENT CLEAN-UP AND LOW DETECTION LIMITS (LODS) THE METHOD WAS COUPLED TO DISPERSIVE LIQUID-LIQUID MICROEXTRACTION (DLLME) PROCEDURE...

THE SAMPLE PREPARATION IS STILL A TEDIOUS NECESSARY STEP BEFORE INSTRUMENTAL ANALYSIS. THIS IS BECAUSE OFTHE COMPLICATION OF THE SAMPLE, THE LOW CONCENTRATION OF THE GOAL ANALYTES, THE EXISTENCE OF A GREAT NUMBER OF POTENTIAL INTERFERES AND EVEN THE MISMATCH WITH THE DETECTION SYSTEM. [1, 2] ...