Obtaining bixin from semi-defatted annatto seeds by a mechanical method and solvent extraction: Process integration and economic evaluation.

This work involves the application of physical separation methods to concentrate the pigment of semi-defatted annatto seeds, a noble vegetal biomass rich in bixin pigments. Semi-defatted annatto seeds are the residue produced after the extraction of the lipid fraction from annatto seeds using supercritical fluid extraction (SFE). Semi-defatted annatto seeds are use in this work due to three important reasons: i) previous lipid extraction is necessary to recovery the tocotrienol-rich oil present in the annatto seeds, ii) an initial removal of the oil via SFE process favors bixin separation and iii) the cost of raw material is null. Physical methods including i) the mechanical fractionation method and ii) an integrated process of mechanical fractionation method and low-pressure solvent extraction (LPSE) were studied. The integrated process was proposed for processing two different semi-defatted annatto materials denoted Batches 1 and 2. The cost of manufacture (COM) was calculated for two different production scales (5 and 50L) considering the integrated process vs. only the mechanical fractionation method. The integrated process showed a significantly higher COM than mechanical fractionation method. This work suggests that mechanical fractionation method is an adequate and low-cost process to obtain a rich-pigment product from semi-defatted annatto seeds.

Comparing the selectivity and chiral separation of d- and l- fluorenylmethyloxycarbonyl chloride protected amino acids in analytical high performance liquid chromatography and supercritical fluid chromatography; evaluating throughput, economic and environmental impact.

The chiral separation of d- and l- FMOC amino acids was undertaken using the Lux Cellulose-1 polysaccharide based chiral column in HPLC (normal phase and reverse phase) and SFC conditions. This was done to compare the relative selectivity and separation between the three separation modes and to evaluate the potential benefits of SFC separations with regards to resolution, throughput, economic and environmental impact. It was established that the separation of d- and l- FMOC amino acids in SFC displayed behaviours that were similar to both normal phase and reversed phase, rather than distinctly one or the other. Additionally, although reversed phase conditions yielded significantly higher resolution values between enantiomers across the range of amino acids studied, improvements in selectivity in SFC via the introduction of higher concentrations of formic acid in the mobile phase allowed for better resolution per unit of time. Moreover since the SFC mobile phase is composed mostly of recyclable CO2, there is a reduction in organic solvent consumption, which minimises the economic and environmental costs.

Stereoselective quantification of triticonazole in vegetables by supercritical fluid chromatography.

A highly fast analytical method though supercritical fluid chromatography (SFC) has been developed to quantify triticonazole enantiomers in cucumbers and tomatoes. Effects of organic modifier type and concentration on chiral separation and quantification of standard solution as well as matrix-matched standard solutions have been studied in detail. Among three organic modifiers, better separation of triticonazole racemate was achieved with 20% ethanol (v/v). The run time in SFC (ca 3min) with CO2-ethanol (80:20, v/v) as the mobile phase was six-fold shorter than HPLC analysis (about 18min). Then, QuEChERS (quick, easy, cheap, effective, rugged and safe) extraction procedure was used for triticonazole in vegetables. The residue analysis method was validated. Good linearity (R2≥0.9988) and recoveries (81.62-106.21%, RSD≤7.30%) for the two enantiomers were achieved. This developed method described herein is convenient and reliable for enantioselective detection of triticonazole in vegetables, which might provide additional information for reliable risk assessment of chiral pesticides.

Advances in LC: bioanalytical method transfer.

There are three main reasons for transferring from an existing bioanalytical assay to an alternative chromatographic method: speed, cost and sensitivity. These represent a challenge to the analyst in that there is an interplay between these three considerations and one factor is often improved at the expense of another. These three factors act as drivers to encourage technology development and support its uptake. The more recently introduced chromatographic technologies may show significant improvements against one of more of these factors relative to conventional 4.6-mm id reversed-phase HPLC. In this article, some of these new chromatographic approaches will be considered in terms of what they can offer the bioanalysts.

Delivering the promise of SFC: a case study.

During the past years there has been a rapid development in supercritical fluid chromatography (SFC) instrumentation making it a highly efficient and robust technique. Although much is written about the advantages of SFC over liquid chromatography (LC), there are not many direct comparisons detailing the gain in purification throughput, the savings in solvent consumption and the reduced environmental impact for large-scale SFC applications. We will show that a research scale separation laboratory built to handle multigram amounts can be used for kilogram separations when moving from LC to SFC.

Fractionation of whey protein isolate with supercritical carbon dioxide-process modeling and cost estimation.

An economical and environmentally friendly whey protein fractionation process was developed using supercritical carbon dioxide (sCO(2)) as an acid to produce enriched fractions of α-lactalbumin (α-LA) and ß-lactoglobulin (ß-LG) from a commercial whey protein isolate (WPI) containing 20% α-LA and 55% ß-LG, through selective precipitation of α-LA. Pilot-scale experiments were performed around the optimal parameter range (T = 60 to 65 °C, P = 8 to 31 MPa, C = 5 to 15% (w/w) WPI) to quantify the recovery rates of the individual proteins and the compositions of both fractions as a function of processing conditions. Mass balances were calculated in a process flow-sheet to design a large-scale, semi-continuous process model using SuperproDesigner® software. Total startup and production costs were estimated as a function of processing parameters, product yield and purity. Temperature, T, pressure, P, and concentration, C, showed conflicting effects on equipment costs and the individual precipitation rates of the two proteins, affecting the quantity, quality, and production cost of the fractions considerably. The highest α-LA purity, 61%, with 80% α-LA recovery in the solid fraction, was obtained at T = 60 °C, C = 5% WPI, P = 8.3 MPa, with a production cost of $8.65 per kilogram of WPI treated. The most profitable conditions resulted in 57%-pure α-LA, with 71% α-LA recovery in the solid fraction and 89% ß-LG recovery in the soluble fraction, and production cost of $5.43 per kilogram of WPI treated at T = 62 °C, C = 10% WPI and P = 5.5 MPa. The two fractions are ready-to-use, new food ingredients with a pH of 6.7 and contain no residual acid or chemical contaminants.

Recent patents on the extraction of carotenoids.

This article reviews the patents that have been presented during the last decade related to the extraction of carotenoids from various forms of organic matter (fruit, vegetables, animals), with an emphasis on the methods and mechanisms exploited by these technologies, and on technical solutions for the practical problems related to these technologies. I present and classify 29 methods related to the extraction processes (physical, mechanical, chemical, and enzymatic). The large number of processes for extraction by means of supercritical fluids and the growing number of large-scale industrial plants suggest a positive trend towards using this technique that is currently slowed by its cost. This trend should be reinforced by growing restrictions imposed on the use of most organic solvents for extraction of food products and by increasingly strict waste management regulations that are indirectly promoting the use of extraction processes that leave the residual (post-extraction) matrix substantially free from solvents and compounds that must subsequently be removed or treated. None of the reviewed approaches is the best answer for every extractable compound and source, so each should be considered as one of several alternatives, including the use of a combination of extraction approaches.

Efficient stripping of photoresist on metallized wafers by a pause flow of supercritical fluid.

Utilization of supercritical fluids (SCFs) is studied here on the premises of a saving of hazardous organic solvents and of the specification for stripping the photoresist (PR) on metallization layers, which is one of the integrated circuit processing modules. By using factorial experimental designs with five factors and four level ranges, this research focuses on determining an optimized recipe with high stripping efficiency and to determine the stripping mechanism. In the case of PR on an aluminum layer, the initial use of the pulse flow mode could increase the extraction ratio remarkably when compared to the conventional continuous flow mode. Based on the limitation of a total volume of 30 mL purging SCF-CO(2) for economical considerations, the optimum conditions can be summarized as follows: 120 degrees C, oven temperature; 350 atm, CO(2) pressure; 0.2 mL of ethylacetate spiking to SCF-CO(2); 2.0 min, static equilibrium time; and five cycles of dynamic flow pausing. A recovery of 94.6% (n=3, RSD=6.5%) was obtained, while the diffusion of stripped PR from substrate matrix prevailed over the dissolution of binding PR into the SCF medium. In the case of copper, the optimum parameters in a pause flow mode were 140 degrees C, oven temperature; 500 atm, CO(2) pressure; 0.75 mL, ethylacetate spiking volume; 5.0 min, static time; and six cycles of flow pausing. These extreme parameters still did not produce an SCF environment suitable for diffusion or dissolution mass transfer, and thus a recovery of 76.2% (n=3, RSD=7.5%) was only obtained. Removing PR coated on a Cu layer was harder than that on an Al layer.

Remediation of contaminated soils using supercritical fluid extraction: a review (1994-2004).

Considerable effort is being made to remediate soils contaminated with petroleum hydrocarbons, polyaromatic hydrocarbons, polychlorinated biphenyls, dioxins, heavy metals and other organic and inorganic compounds that have resulted from industrial activities, accidental spills and improper waste disposal practices. Current remediation technologies may be limited when treating certain types of contaminated soils and therefore new, efficient and cost effective technologies are being investigated. Supercritical fluid extraction is a potential remediation technology for contaminated soils. It is a simple, fast and selective solvent extraction process that uses a supercritical fluid as the solvent. A commonly used fluid is carbon dioxide at pressures and temperatures greater than 7.4 MPa and 31 degrees C, respectively. In supercritical fluid extraction, the extracted contaminants first dissolve into the supercritical solvent and then these contaminants are separated from the supercritical solvent via a simple change in pressure and temperature conditions or by using a separation process. This paper provides a review of supercritical fluid extraction and its application to the remediation of contaminated soils. This review focuses on the removal of organic contaminants (such as petroleum hydrocarbons, polyaromatic hydrocarbons, polychlorinated biphenyls and others) and inorganic contaminants (such as heavy metals and radioactive elements) from soils. Recent data (1994-2004) on the supercritical fluid extraction of spiked soils and field-contaminated soils were collected. The success of supercritical fluid extraction as a method for removing these contaminants from soils is highlighted and some of the future research needed to develop it as a commercial-scale economic remediation technology are discussed.

Impacts of extraction methods in the rapid determination of atrazine residues in foods using supercritical fluid chromatography and enzyme-linked immunosorbent assay: microwave solvent vs. supercritical fluid extractions.

It is an accepted fact that many food products that we eat today have the possibility of being contaminated by various chemicals used from planting to processing. These chemicals have been shown to cause illnesses for which some concerned government agencies have instituted regulatory mechanisms to minimize the risks and the effects on humans. It is for these concerns that reliable and accurate rapid determination techniques are needed to effect proper regulatory standards for the protection of people's nutritional health. This paper, therefore, reports the comparative evaluation of the extraction methods in the determination of atrazine (commonly used in agricultural as a herbicide) residues in foods using supercritical fluid chromatography (SFC) and enzyme-linked immunosorbent assay (ELISA) techniques. Supercritical fluid extraction (SFE) and microwave solvent extraction (MSE) methods were used to test samples of frozen vegetables, fruit juice, and jam from local food markets in Houston. Results showed a high recovery percentage of atrazine residues using supercritical fluid coupled with ELISA and SFC than with MSE. Comparatively, however, atrazine was detected 90.9 and 54.5% using SFC and ELISA techniques, respectively. ELISA technique was, however, less time consuming, lower in cost, and more sensitive with low detection limit of atrazine residues than SFC technique.