Sample preparation sonication

Sample preparation Sonicate 2 mg tablet in MeOH, make up to 20 mL with MeOH, filter (0.45 p,m), dilute 5 mL filtrate to 100 mL with MeOH, iiyect a 20 p-L aliquot. 

Sample preparation Sonicate 50 million leukemic cells in 1 mL phosphate buffered saline. 500 pL Plasma or 1 mL sonicated cells + 0.5 (cells) or 2.5 (plasma) pg teniposide + 2 mL chloroform, mix. Remove the organic layer and evaporate it to diyness under a stream of nitrogen, reconstitute the residue in 200 pL MeOH water 50 50, sonicate for 5 min, inject a 100 pL aliquot. To measure non-protein-boimd etoposide filter (Amicon Centrifree) while centrifuging at 20°, inject a 100-200 pL aliquot of the ultrafiltrate. 

Sample preparation Sonicate lysed cells for 5 min, filter (0.2 pm PTFE), add timolol, inject an aliquot. 

Sample preparation Sonicate in mobile phase, dilute the clear supernatant to a concentration of 3-10 M,g/mL, filter (0.5 (xm), inject an aliquot. 

Sample preparation Sonicate 100- 500 mg resin in 3 mL MeOH for 10 min, centrifuge, repeat extraction twice more. Combine the supernatants and make up to 10 mL with MeOH, filter (0.45 pm), inject a 10 pL aliquot. 

Sample preparation Sonicate tablet in 5 mL EtOH, make up to 10 mL with mobile phase, centrifuge at 2700 g for 10 min. Dilute a 500 xL aliquot of the supernatant to 10 mL with mobile phase, inject an aliquot. 

Sample preparation Sonicate 300 xL whole blood, 600 p,L water, and 5 mL MeOH containing 0.01% BHT for 1 min, add 10 mL chloroform (Caution Chloroform is a carcinogen ), sonicate for 1 min, vortex for 30 s, let stand at room temperatme for 1 h, add 5 mL water, mix for 5 s, centrifiige at 2600 g for 10 min. Evaporate the lower organic layer to dryness under a stream of nitrogen, reconstitute the residue with 300 xL chloroform MeOH 95 5, inject a 10 xL aliquot. 

Sample preparation Sonicate powdered tablet containing 500 mg metformin and 30 mg pioglitazone with 100 mL 100 mM HCl for 10 min with intermittent shaking, add 40 mL MeCN, sonicate for 25 min with intermittent shaking, cool to room temperature, add 10 mL MeCN, make up to 200 mL with 100 mM HCl, mix well, centrifuge at 10 000 rpm for 10 min. Mix a 2 mL aliquot with 1 mL 250 p,g/mL IS in MeCN 100 mM HCl 25 75, make up to 50 mL with diluent, inject an aliquot. (The diluent was MeCN 5 mM disodium hydrogen phosphate 30 70, adjusted to pH 2.3 with HCl.)... 

Sample preparation Sonicate cells, extract twice with 3 mL portions of ethyl acetate by vortexing for 1 min, centrifuge at 1000 rpm for 5 min. Evaporate the combined organic layers to dryness under a stream of nitrogen, reconstitute the residue with 1 mL MeOH, vortex for 1 min, evaporate to dryness, reconstitute the residue with 100 p,L MeOH, centrifuge, inject a 20 [xL aliquot. 

Sample preparation Sonicate a finely powdered tablet with 50 mL MeCN for 10 min, m e up to 100 mL with MeCN, filter (Whatman No. 42 paper), dilute a 1 mL ahquot to 100 mL with MeCN, inject a 20 p,L aliquot. 

Sample preparation Sonicate finely ground tablets in MeOH for 5 min, centrifuge, dilute with MeOH containing 290 ng/mL IS, inject a 20 tL aliquot. 

Specifically for triazines in water, multi-residue methods incorporating SPE and LC/MS/MS will soon be available that are capable of measuring numerous parent compounds and all their relevant degradates (including the hydroxytriazines) in one analysis. Continued increases in liquid chromatography/atmospheric pressure ionization tandem mass spectrometry (LC/API-MS/MS) sensitivity will lead to methods requiring no aqueous sample preparation at all, and portions of water samples will be injected directly into the LC column. The use of SPE and GC or LC coupled with MS and MS/MS systems will also be applied routinely to the analysis of more complex sample matrices such as soil and crop and animal tissues. However, the analyte(s) must first be removed from the sample matrix, and additional research is needed to develop more efficient extraction procedures. Increased selectivity during extraction also simplifies the sample purification requirements prior to injection. Certainly, miniaturization of all aspects of the analysis (sample extraction, purification, and instrumentation) will continue, and some of this may involve SEE, subcritical and microwave extraction, sonication, others or even combinations of these techniques for the initial isolation of the analyte(s) from the bulk of the sample matrix. 

Isolation of the products from complex matrixes (e.g. polymer and water, air, or soil) is often a demanding task. In the process of stability testing (10 days at 40 °C, 1 h at reflux temperature) of selected plastic additives (DEHA, DEHP and Irganox 1076) in EU aqueous simulants, the additive samples after exposure were simply extracted from the aqueous simulants with hexane [63]. A sonication step was necessary to ensure maximum extraction of control samples. Albertsson et al. developed several sample preparation techniques using headspace-GC-MS [64], LLE [65] and SPE [66-68]. A practical guide to LLE is available [3]. 

Table 3.4 summarises the main characteristics of a variety of sample preparation modes for in-polymer additive analysis. Table 3.5 is a short literature evaluation of various extraction techniques. Majors [91] has recently reviewed the changing role of extraction in preparation of solid samples. Vandenburg and Clifford [4] and others [6,91-95] have reviewed several sample preparation techniques, including polymer dissolution, LSE and SEE, microwave dissolution, ultra-sonication and accelerated solvent extraction. 

In order to increase the overall extraction efficiency during SFE sonication has been applied [352]. Ultrasound creates intense sinusoidal variations in density and pressure, which improve solute mass transfer. Development of an SFE method is a time-consuming process. For new methods, analysts should refer the results to a traditional sample preparation method such as Soxhlet or LLE. 

Samples are usually prepared by weighing a 25 mg sample of drug substance and placing it into an appropriate vial. One millileter of organic solvent, such as methanol, is then added to the vial. The sample is sonicated for 1-2 min, until solution is clear, and now ready to be applied to HPTLC plates. 

This chapter provides the novice and the experienced analyst with an overview of sample preparation techniques focusing on solid dosage forms. It describes the best practices in the dilute and shoot approach, and the tricks of the trade in grinding, mixing, sonication, dilution and filtration of drug products. Selected case studies of sample preparations for assays and impurity testing are used to illustrate the strategies, trade-offs... 

Sample preparation. sample weight shaking or dissolution time sonication time... 

The organoarsenical particulates are extracted ultrasonically from the filters for 30 minutes in 25 mL of an aqueous carbonate/ bicarbonate/borate buffer (Eluent 1, Table I). After sonication the resulting extracts are ready for analysis and no further sample preparation is necessary. 

Samples underwent sonication in hot, soapy water for 15 minutes, to ensure surfaces were clean and free of any surface contamination. The more elaborate preparation method of Carter (10, 13) was not utilized because visual and 7-30X microscopic examination of each coin revealed no remaining encrustation or patination. 

Equipment for Sample Preparation and Analysis 1. Needle manifold for drying samples with a nitrogen stream 2. Probe sonicator with narrow tip and variable, pulsatile energy delivery 3. Lyophilizer for drying diet-drug admixtures and feces... 

Pyrene and naphthalene were purified by zone refinement for more than 130 passes (Bridgmen method). After such purification the central part of the glass ampoule was extracted and used in the sample preparation. Drop coating of the pyrene (naphthalene) with SWNT suspension in toluene on a quartz substrate was used to form a thin film for Raman measurements. The film was deposited onto the quartz substrate from nanotube suspension in toluene (0.1 mg/mL) and from suspension of nanotube with pyrene (or naphthalene) after short sonication (20 minutes 44 kHz). The weight ratio was 1 1 and 1 4 for mixture with pyrene (samples PI and P2, respectively) and 1 1 with naphthalene (sample N). 

Had the QC laboratory been consulted during the development stage, the chemist would have suggested that sample preparation be done in a 100-ml volumetric flask followed by a 5-ml to 50-ml dilution. With this procedure, the QC chemist would be more productive since more flasks could be sonicated and shaken at once, 10 to 12 flasks could be easily carried using a sample tray, and 85% less sample diluent needed to be prepared. This more than made up for the dilution step. 

One example of suspending or dissolving a solid in solution is seen in USP method 467, which provides an approach for the analysis of methylene chloride in coated tablets. The sample preparation procedure calls for the disintegration of 1 g of tablets in 20 mL of organic-free water via sonication. The solution is centrifuged after sonication, and 2 mL of the supernatant solution is transferred to a HSAS vial and then analyzed by HSGC [12]. 

A sensitive reverse-phase HPLC method has been developed for the analysis of etodolac in tablet formulation [22]. The chromatographic separation was achieved using a reverse-phase Cu column, having dimensions of 3.3 cm x 0.46 cm i.d. (3 pm particles) and which was maintained at 30°C. The mobile phase consisted of pH 6.0 phosphate buffer / methanol (60 40 v/v), and was eluted at 1 mL/min. Analyte detection was effected on the basis of UV detection at 230 nm. Diazepam was used as an internal standard. The sample preparation entailed grinding the etodolac tablets, followed by extraction with methanol (using sonication). A retention time of 1.46 min was obtained for etodolac under these conditions, and the method was found to be linear, precise, and accurate over the concentration range of 0.01 to 0.1 mg/mL. 

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