Microwave-assisted process (MAP™): a new tool for the analytical laboratory

Paré, J. R. Jocelyn; Bélanger, Jacqueline M.R.; Stafford, Sally S.

doi:10.1016/0165-9936(94)87033-0

Cited by 243 publications

(9 citation statements)

References 11 publications

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“…Moreover, many bioactive compounds are thermally labile, so they are degraded at high temperatures [10]. Microwave-assisted extraction is considered a novel method for extracting soluble products into a fluid from a wide range of materials [12]. The extraction mechanism of microwave-assisted extraction involves three sequential steps.…”

Section: Introductionmentioning

confidence: 99%

Conventional and microwave-assisted extraction for bioactive compounds from dried coffee cherry peel by-products and antioxidant activity of the aqueous extracts

Thaiphanit¹,

Wedprasert²,

Srabua³

2020

ScienceAsia

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The purposes of this research are to measure the chemical composition, bioactive compounds and antioxidant activities in dried coffee cherry peel by products from the mature fruits of Arabica and Robusta coffee beans and to determine the effects of conventional and microwave-assisted extraction techniques on the quantities of those compounds and antioxidant activities in aqueous extracts. Bioactive compounds from the by-products were extracted with water using either conventional or microwave-assisted extraction equipment at temperatures of 80, 90 and 100°C or at microwave power settings of 450, 630 and 900 W, respectively, for various time period (1-5 min). The results showed that Arabica coffee cherry peel extracts exhibited significantly higher levels of bioactive compounds (except total carotenoids) and antioxidant activities than the Robusta coffee cherry peel extracts. The highest quantities of bioactive compounds in the aqueous extracts were found with conventional extraction. However, microwave-assisted extraction was far more efficient for compounds with antioxidant activity. The optimum extraction process for caffeine and carotenoids was a conventional extraction at 100°C with a 5 min holding time using either Robusta or Arabica coffee cherry peels.

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Section: Introductionmentioning

confidence: 99%

Conventional and microwave-assisted extraction for bioactive compounds from dried coffee cherry peel by-products and antioxidant activity of the aqueous extracts

Thaiphanit¹,

Wedprasert²,

Srabua³

2020

ScienceAsia

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“…Product samples were extracted using microwave –assisted process [7–9] with PTFE-HT tubes, HTR -300/6 s dissociation with pressure-calibration system (PCS) from MLC (Mikrowellen Laborsysteme, Leuterbach, Germany). Material samples as well as blood and urine samples were quantified using atomic absorption spectrometer [10] with automatic sampler system (Thermo Fisher Scientific, Dual AA Spectrometer ICE 3500, Freiburg, Germany).…”

Section: Resultsmentioning

confidence: 99%

Alternative drugs go global: possible lead and/ or mercury intoxication from imported natural health products and a need for scientifically evaluated poisoning monitoring from environmental exposures

Budnik

Baur

Harth

et al. 2016

J Occup Med Toxicol

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BackgroundWith increases in globalization, cultural remedies from Chinese, Ayurvedic, Arab and other traditions have become more available to international consumers, offering unfamiliar “Natural Health Products” (NHP), used as alternative medicine or supplementary medicine.Contamination with toxic ingredients including lead, mercury, arsenic, and other toxic elements has been documented in several of these products from various parts of the globe, particularly from some parts of Asia and the Orient.FindingsWe have been following this development in the last 6 years and have analyzed n = 20 such products (60 analyses) from patients with intoxication symptoms in a pilot study, showing alarming high concentrations of mercury and/or lead (the first one in “therapeutic” doses). 82 % of the studied NHP contained lead concentrations above the EU limit for dietary supplements. 62 % of the samples exceeded the limit values for mercury. Elevated blood lead and mercury levels in patients along with clinical intoxication symptoms corroborate the causal assumption of intoxication (s). We present one detailed clinical case report of severe lead and mercury intoxications and give an overview about blood concentration related symptoms and signs of n = 41 case reports of mercury intoxications of the German monitoring BfR-DocCenter.ConclusionsFor NHP there is evidence on a distinct toxicological risk with alarming low awareness for a possible intoxication which prevents potentially life-saving diagnostic steps in affected cases. In many cases patients do not communicate the events to their physicians or the local health authority so that case reports (e.g. the BfR-DocCentre) are missing. Thus, there is an urgent need to raise awareness and to initiate more suitable monitory systems (e.g. National Monitoring of Poisonings) and control practice protecting the public.

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“…The MAE extraction process is based inherently on the capability of a given matrix to absorb microwave energy. The amount of absorption varies with the chemical nature of the species that are irradiated with microwaves [15]. One of the parameters that is used to analyze how large the energy absorption could be is the dielectric constant.…”

Section: Closed-vessel Microwave-assisted Extraction Methodsmentioning

confidence: 99%

Total Fat Gravimetric Method Workflow in Portuguese Olives Using Closed-Vessel Microwave-Assisted Extraction (MAE)

Lourenço

Ettlin²,

Cardoso³

et al. 2021

Foods

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A simple and rapid method for the quantitation of total fat in olive samples is designed, evaluated, and presented. This method is based on an innovative closed-vessel microwave-assisted extraction (MAE) technique. A method was designed for olives, and some figures of merits were evaluated: limit of detection (LOD), limit of quantification (LOQ) and expanded uncertainty (U). The data obtained in these experiences show that the workflow of the MAE method in a closed container is statistically equivalent to the other two methods, showing in this case better performance indicators (LOD = 0.02%, LOQ = 0.06%, and U = 15%). In addition, it is also demonstrated that the complete MAE method workflow allows the determination of total fat in a maximum of 12 analyses simultaneously for about 100 min in each run, which is the capacity of the rotor. This is a much better productivity when compared to the traditional Soxhlet-based method. Considering the sample workflow, the closed-vessel MAE method greatly simplifies sample handling, therefore minimizing sample loss during sample preparation and reducing analysis time. When MAE is compared to NIR-based methods, the advantage comes from there being no need for any type of calibration in the sample matrix. The MAE method itself can be used to determine the reference value for NIR calibration purposes. The results obtained for CRM using MAE were equivalent to the ones shown on the certificate.

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Microwave-assisted process (MAP™): a new tool for the analytical laboratory

Cited by 243 publications

References 11 publications

Conventional and microwave-assisted extraction for bioactive compounds from dried coffee cherry peel by-products and antioxidant activity of the aqueous extracts

Conventional and microwave-assisted extraction for bioactive compounds from dried coffee cherry peel by-products and antioxidant activity of the aqueous extracts

Alternative drugs go global: possible lead and/ or mercury intoxication from imported natural health products and a need for scientifically evaluated poisoning monitoring from environmental exposures

Total Fat Gravimetric Method Workflow in Portuguese Olives Using Closed-Vessel Microwave-Assisted Extraction (MAE)

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