disposable pipette extraction
Recently Published Documents


TOTAL DOCUMENTS

54
(FIVE YEARS 33)

H-INDEX

15
(FIVE YEARS 3)

2021 ◽  
Vol 1 (3) ◽  
pp. 31-38
Author(s):  
Prisma Andini Mukti ◽  
Sulaeman Mappasessu ◽  
Yuswardi Mappasessu ◽  
Triwidiastuti Andini Mukti ◽  
Dwi Hernanto ◽  
...  

Method analytical validation and verification is crucial in routine qualitative and quantitative analysis. Analysis laboratory need objective evidences about specific parameters in their drugs/analytes or drugs metabolites in matrices biology. Urine is the most preferable matrix biology for determining drugs metabolites especially in drug abuses cases because urine’s sampling process is not invasive. There are many methods extracting drugs in urine, especially methamphetamine and amphetamine as those two analytes are excreted via urine. This study presented method verification for determination of methamphetamine and amphetamine in urine using Gerstel® automated Disposable Pipette Extraction (DPX) Multipurpose Sampler (MPS). Result of this study showed that retention time of methamphetamine is in minute 6.21, and amphetamine is in minute 3.15. Methampethamine’s curve displayed a coefficient of determination r2=0,9999 with the equation y=170,19x+33183. The equation of amphetamine showed y=44390x – 17513 with coefficient of determination r2= 0,9974. Limit of detection (LOD) of methamphetamine in urine is 59,73 ppb, and LOD of amphetamine is 36 ppb.


Author(s):  
Ludmyla Tavares ◽  
Ricardo Bernardo ◽  
Anselmo de Oliveira ◽  
Boniek Vaz ◽  
Andrea Chaves

This study proposes a new, efficient, and selective method for the analysis of cocaine in oral fluid. For this purpose, an extractive phase with restricted access materials (RAM) capable of extract and pre-concentrate low molecular weight analytes and simultaneously exclude macromolecules was developed for disposable pipette extraction (DPX) followed by liquid chromatography coupled to mass spectrometry (LC-MS) analyses. The proposed method was optimized using a 24 factorial design which pointed higher extraction efficiency under the following conditions: pH 9, 10 cycles of extraction (aspirate/dispense), 3 cycles of desorption (aspirate/dispense) and acetonitrile as desorption solvent. The DPX-RAM/LC-MS method showed linearity range from 10 to 100 ng mL-1 with determination coefficient (R2) = 0.999, accuracy values ranged from -0.9 to 4.3%, precision values ranged from 1.7 to 9.1% and recovery values ranged from 97.9 to 101.1%. The benefits of this method are that it can be performed in few minutes and that the analytical performances, including the limit of detection (3.13 ng mL-1), limit of quantitation (10 ng mL-1) and linear range were found to be in agreement with other methods used for similar analysis.


Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5703
Author(s):  
Xijuan Tu ◽  
Wenbin Chen

As the main source of nutrients for the important pollinator honeybee, bee pollen is crucial for the health of the honeybee and the agro-ecosystem. In the present study, a new sample preparation procedure has been developed for the determination of neonicotinoid pesticides in bee pollen. The neonicotinoid pesticides were extracted using miniaturized salting-out assisted liquid-liquid extraction (mini-SALLE), followed by disposable pipette extraction (DPX) for the clean-up of analytes. Effects of DPX parameters on the clean-up performance were systematically investigated, including sorbent types (PSA, C18, and silica gel), mass of sorbent, loading modes, and elution conditions. In addition, the clean-up effect of classical dispersive solid-phase extraction (d-SPE) was compared with that of the DPX method. Results indicated that PSA-based DPX showed excellent clean-up ability for the high performance liquid chromatography (HPLC) analysis of neonicotinoid pesticides in bee pollen. The proposed DPX method was fully validated and demonstrated to provide the advantage of simple and rapid clean-up with low consumption of solvent. This is the first report of DPX method applied in bee pollen matrix, and would be valuable for the development of a fast sample preparation method for this challenging and important matrix.


Sign in / Sign up

Export Citation Format

Share Document