Manual extraction

Although manual extraction of information from herbal texts is straightforward (Fig. 4.3A), the work is labor intense and requires many areas of expertise (Fig. 4.3B). Historians must provide context for the language. Botanists are necessary to update the names and correctly identify the plants discussed. Physicians and biomedical scientists are required to extrapolate the potential pharmacological function of the plant compounds used to treat a certain disorder in the text. Luckily, the use of bioinformatics to extract this information can be more efficient than manual extraction [7]. 

It is possible to extract novel drug leads from historic herbal texts. However, manual extraction techniques are laborious. The automated extraction system we have developed makes it possible to identify potential novel drug leads in a high-throughput fashion. 

On the other hand, quantitative extraction requires complete and exhaustive extraction and no material can be lost. To assure complete extraction when a food is analyzed for the first time in a laboratory, it is useful to carry out two or three extractions, pool the solvents, and keep separate the next extracts to verify the presence of carotenoids. Usually four to six extractions are enough to remove the carotenoids completely from a sample. The extraction can be carried out in a blender, vortex, or with a mortar and pestle. Accelerated solvent extraction (ASE), an important extraction technique in residue analysis, currently attracts interest due to its short duration, low level of solvent use, and high extraction yield. The average recoveries for all carotenoids with the exception of norbixin ranged from 88.7 to 103.3% using manual extraction and from 91.0 to 99.6% by ASE (70 bar and temperature of 40°C) both extractions were carried out with a mixture of MeOH, EtOAc, and petroleum ether (1 1 1). ... 

Automation using a robotic liquid handling system eliminated most of the tedious steps encountered with traditional manual extraction procedures. Automated 96-well SPE and LLE techniques using robotic liquid handlers have been successfully implemented to support high-throughput bioanalysis.5... 

Bone marrow is the natural site of hematopoiesis and was therefore the first source of hematopoietic stem and progenitor cells. In addition to the hematopoietic cells primary stroma can also be collected simultaneously from this source. However, as the harvesting of cells from bone marrow is an invasive procedure that requires manual extraction under spinal or general anesthesia, alternative sources are preferred whenever possible, although, for allogeneic stem cell transplantation, bone marrow is still the source of choice [23]. 

Nitrous oxide appears to have little effect on uterine musculature. However, the halogenated anesthetics are potent uterine muscle relaxants and produce this effect in a concentration-dependent fashion. This pharmacologic effect can be used to advantage when profound uterine relaxation is required for an intrauterine fetal manipulation or manual extraction of a retained placenta during delivery. However, it can also lead to increased uterine bleeding. 

In an early study Turpeinen and Stenman [99] published a negative-ion MRM ES-MS/MS method for urinary cortisol. The internal standard used was 6a-methyl-prednisolone and manual extraction was employed. Both steroids eluted within 6 min from the microbore column, but the total run and equilibration time was not reported. The transitions monitored were m/z 361—>331 for cortisol and m/z 373—> 343 for internal standard. The sample size was 1 ml. 

Fredline et al. [18] report an MRM negative-ion ESI method for aldosterone using flumethasone as an internal standard. The MRM transition used was 359—>331. The assay was linear over a 15- to 5000-pg/ml range and the limit of quantitation was 15 pg/ml. A manual extraction was used and recovery and accuracy were excellent. 

Bockhardt et al. (78) derived a manual extraction and automated [4-(4-dimethyl-aminophenylazo)benzensulfonyl] derivatization procedure from the method previously proposed by Krause et al. (44). Reversed-phase HPLC was carried out on a Spherisorb ODS-2 column at 50°C with gradient elution and detection at 436 nm, reaching detection limits (DLs) of 0.3-0.8 pmol. 

The first "real-sample" application is given in Table IX, where chlorpyrifos was extracted from treated grass supplied by an outside collaborating laboratory. Two instruments were used for this application, extracting 11 samples on 4/26/89 and 8 samples on 10/13/90. The relative standard deviations were 3.9% and 1.7% respectively. The latter value is extraordinarily good since, in the work reported, precision due to the chromatographic analysis variability was between 1% and 3%. Further, the values of precision reported by the supplier for manual extraction of chlorpyrifos from similar matrices, leaves and roots, were 8% and 4% respectively. 

SPE initially comes in the form of a packed syringe-shaped cartridge for manual extraction, and then followed by 96-well plate each of which can be mounted on its specific type of extraction manifold. The first generation of SPE stationary phases was made of silica backbone bonded to hydrocarbon chain of variable length such as C18, C8, and phenyl. The second generation of SPE stationary phases was still primarily made of silica backbone but with more modification for these functional groups. 

Another advanced and novel sample preparation technique is online solid phase extraction (online SPE). Although the extraction mechanism is as the same as traditional offline SPE, online SPE offers several advantages. Because sample preparation is carried out during analysis, it eliminates the time needed for sample preparation thus increases throughput significantly. Additionally, because the entire sample is eluted to the LC-MS/MS system, it may increase assay sensitivity. Finally, because there is no manual extraction involved, it may reduce human error, potential contamination, and inconsistent recovery. 

Type of gun—A low success rate for FDR detection has been observed for casework involving. 22 caliber revolvers and rifles, and for shotguns which are usually closed breech weapons, some rifles, namely, bolt action, require manual extraction of the spent cartridge case consequently the design of the firearm can have an influence on the quantity of FDR deposited. 

Gamiz-Gracia and de Castro (2000) devised a subcritical extractor equipped with a three-way inlet valve and an on/off outlet valve to perform subcritical water extractions in a continuous manner for the isolation of fennel essential oil. The target compounds were removed from the aqueous extract by a single extraction with 5 ml hexane, determined by gas-chromatography-flame ionization and identified by mass spectrometry. This extraction method is superior to both hydrodistillation and dichloromethane manual extraction in terms of rapidity, efficiency, cleanliness and the possibility of manipulating the composition of the extract. 

Sample preparation is the critical and most labor-intensive part of tocol analysis, and several attempts have been made to simplify it. By using accelerated extraction techniques it has been possible to work up more samples with good repeatability than by manual extraction. This is vital when the number of samples is large and analyses are performed regularly, e.g. in screening and follow-up studies. However, when a complete extraction yield is needed, the extraction should be carefully optimized with careful consideration of the chemical and physical properties of the sample matrix and tocols. 

Fig. 7.19. Chromatograms obtained in the separation of methylmercury from DORM-1 CRM extracts using (A) manual extraction, (B) supercritical fluid extraction and (C) microwave-assisted extraction. (Reproduced with permission of the American Chemical Society.)...

In situations where a lower detection fimit is required and highly specific antisera are not available, cortisol is first extracted from serum before measurement. The extraction is performed in a manner similar to that for urine specimen extractions (see discussion later in this chapter). An important advantage of the direct assays is their superior precision compared with assays involving extraction. In part this may reflect the variability inherent in manual extraction techniques. In general, however, with the high specificity of the antibodies available today and with the use of very sensitive nonisotopic techniques, such as chemiluminescence and fluorescence, the quantitative measurement of cortisol in blood and urine is now relatively straightforward. 

Until around 1970 the instruments were connected to a pen recorder where continuous measurements were drawn on analogue charts. Afterward hourly values were manually extracted and written on papers. Around 1970 the pen recorder was replaced with a potentiometer and a paper tape puncher enabling automatic transfer of data to a computer at DMI afterward. Around 1990 all stations changed to automatic real-time data transmission allowing online communication of data to a computer at DMI. 

Despite the aforementioned benefits and supplementary information provided, kinetic methods are tedious and time consuming, use large amounts of sample and reagents, and so far have been limited to single extractions. In fact, the analytical procedure requires as many manual extractions as data points in the extractrogram. 

For field application, the sonication step for acetonitrile extraction can be replaced by 10 min of manual extraction with hand. This procedure has been compared to sonication and led to similar results [3],... 

Supercritical fluid extraction (SFE) has also been used for the extraction of MMHg from sediments. ° Lorenzo et al. ° compared manual, microwave assisted techniques and SFE for the extraction of Hg from aquatic sediments. Higher recoveries were obtained with microwave extraction techniques compared to manual extraction techniques and SFE. 

A sensitive HPLC multimethod was developed by BreithaupT for the determination of the carotenoid food additives (CFA) norbixin, bixin, capsanthin, lutein, canthaxanthin, b-apo-80-carotenal, b-apo-80-carotenoic acid ethyl ester, b-carotene, and lycopene in processed food using an RP C30 column. For unequivocal identification, the mass spectra of all analytes were recorded using LC-(APcl) MS. For extraction, a manual process as well as accelerated solvent extraction (ASE) was applied. Important ASE parameters were optimized. ASE was used for the first time to extract CEA from various food matrices. Average recoveries for all analytes ranged from 88.7% to 103.3% (manual extraction) and from 91.0% to 99.6% (ASE), with the exception of norbixin using ASE (67.4%). Limits of quantitation (LOQ) ranged from 0.53 to 0.79 mg/L. The presented ASE method can be used to monitor both, forbidden application of CFA or the compliance of food with legal limits. 

Figure 6 Use of SPME for in-tube time-weighted average sampling where C= concentration, Cs = concentration of analyte in the sample, Z= distance between needle opening and position of extraction phase, and f. = length of SPME needle (A) schematic, (B) adaptation of commercial SPME manual extraction holder.

Pineapple leaves from which PALF are extracted are about 70-90 cm in length and 5-7.5 cm in width. Figure 12.2a shows the sword-shaped, dark green pineapple leaves, while Fig. 12.2b shows the extracted PALF bundles from the leaves. Manual extraction process can extract at least 3 % of fibers from the leaves (Paul 1980). PALF are strong, white, and with a silky luster (Fig. 12.2c) and they are usually used to produce rope, broom, mat, nets, and cloths (Bhaduri et al. 1983). 

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