Glycerol blanking

E514 Earl, R.E., Studts, D.J. and Markin, R.S. (1989). Glycerol blanked triglyceride measurement on the Hitachi 705 chemistry analyzer. Clin. Chem. 35, 1072, Abstr. 34. 

An ad hoc panel convened to consider the necessity for glycerol blanking in routine practice recommended blank corrections for specimens from inpatients but not outpatients because of the increased likelihood of free glycerol increases in the former. In practice, however, blanking is usually practiced only by research laboratories and those supporting Upid clinics, particularly to facilitate participation in the CDC standardization program. 

Glycerol blanking. The NCEP Working Group on Lipoprotein Measurement endorses the following recommendations, adapted from the Lipids and Lipoproteins Division of the American Association for Clinical Chemistry ... 

Glycerol blanking of triglyceride measurements must be done in laboratories participating in the CDC Lipoprotein Standardization Program and is recommended for laboratories that specialize in assessment of lipid status, have large populations of hyperlipidemic subjects, or participate in clinical or basic research. 

Glycerol blanking of triglyceride analyses does not have to be routinely conducted on outpatient samples unless economically feasible. However, because of the potential for higher glycerol concentrations in hospital inpatient specimens, all inpatient specimens should be routinely glycerol blanked. 

Cole TG. Glycerol blanking in triglyceride assays is it necessary Clin Chem 1990 36 1267-8. 

T. C. Lee, B. Malone, M. L. Blank, V. Fitzgerald, F. Snyder, Regulation of the Synthesis of Platelet-Activating Factor and Its Inactive Storage Precursor (l-Alkyl-2-acyl-sw-glycero-3-phosphocholine) from 1-Alky 1-2-acety 1-mi-glycerol by Rabbit Platelets , J. Biol. Chem. 1990, 265, 9181-9187. 

A sample of phenol glycerol injection was dilutee with water and an aliquot was taken and reacted with excess bromine generated from potassium bromide and potassium bromate solutions. The excess bromine remaining after reaction was reacted with potassium iodide and the liberated iodine was titrated with sodium thiosulphate. A blank titration was carried out where the same quantity of bromine was generated as was used in the titration of the diluted injection, potassium iodide was then added and the liberated iodine was titrated with sodium thiosulphate. From the following data calculate the percentage of w/v of the phenol in the injection. 

The volume of 0.1015 M sodium thiosulphate required to titrate the bromine blank = 48.9 ml. Density of glycerol = 1.26. 

Filters. HN03 is efficiently trapped out on nylon filters. Typically, two or more filters are connected in series. A schematic of such a filter pack was shown in Fig. 11.22 (Anlauf et al., 1988). A Teflon filter first removes particles from the airstream and a nylon filter then removes gaseous HNO,. In this particular system, a third filter (Whatman 41 impregnated with an aqueous solution of glycerol and citric acid) was used to trap NH3. After sample collection, each of the filters is extracted separately and nitrate, ammonium, and additional particle components collected on the Teflon filter are measured by ion chromatography. The sensitivity of this method for nitric acid and the other species is determined in part by filter blank values (i.e., nitrate on unexposed filters) and by the total amount collected and hence the sampling time used. Times of... 

Then, % NG = 2.523VN/0.1W, where V is the vol of Ti(III) corrected for a blank, N is the normality of the Ti(Ilt), and W is the weight of the NG sample. Variations of this redox titration may be found in Refs 3, 4 8 Determination of Purity of NG by the Dewarda Method. This method involves the saponification of NG to glycerol and nitrate ion. The latter is.then reduced with Dewarda s alloy, a mixture of Al, Zn and Gi. The resultant ammonia is thin distd out and titrated (Refs 2, 5, 10 St 17)... 

Moisturizing ingredients have been used widely in skin care products for the treatment of dry skin for many years. In fact the use of oils for smoothing skin is reported as early as 2300 b.c., although it was not until the work of Blank in the 1950s1 that research focused on water-imbibing substances to retain moisture in the SC. This section will discuss briefly the effects of PCA, urea, glycerol, and lactic acid on human SC function in vivo. 

A sample of fat, weighing 5 0.1 g is saponified in glycerol-sodium hydroxide solution. The saponified sample is acidified with dilute sulfuric acid, followed by distillation of the volatile fatty acids. A volume of 110-mL distillate is collected, chilled to 15°C, and filtered. The filtrate is titrated with 0.1 A sodium hydroxide. A blank determination is carried. 

The equation assumes an average molecular weight of 885 g/mole (triolein) for plasma triglycerides. In addition, because of the preliminary extraction and adsorption steps, the CDC reference method measures only the glycerides, and does not include free glycerol, the so-called triglyceride blank. 

Castor oil contains a triglyceride of ricinoleic acid which is hydrolyzed by intestinal lipases to glycerol and ricinoleic acid, which has cathartic effects. Allergic reactions such as angioedema, rhinitis, asthma, and scarlatiniform rashes have been described but seem to be rare reactions to this common laxative (Bennett and Schwartz 1934 Blank 1945). 

Titrimetric determination The mannitol or glycerol acid-base titration procedure is applied to the dissolved sodium carbonate melt for the determination of milligram amounts of B2O3. A blank prepared from a glass that does not contain boric oxide should be subjected to the same procedure. There are certain interferences the effect of fluoride is eliminated by adding calcium carbonate to the fusion mixture lead and zinc can be filtered off after dissolution of the melt phosphate is precipitated by addition of iron(ni) chloride. The influence of some interference from such elements as aluminum or titanium can be eliminated by adding ethylenediaminetetraacetic acid (EDTA). 

UHMWPE samples were incubated in a 20% BSF solution in PBS at 37 for 1 h and 24 h. After the incubation time, samples were rinsed with PBS and pure water and incubated at 24 C for 1 h in 2 ml of 80% acetonitrile solution, to allow protein desorpdoa Blank samples, not incubated in BSF. were used as controls. Subsequently the acetonitrile solutions were concentrated under nitrogen flow, and proteins were dissolved in sample buffer containing Tris-HCl. SDS. glycerol, mer-captoethanol and bromophenol blue. Samples were then heated at 95 for 5 min before being loaded in the gel. 

In these and other methods a correction may be applied for the small amount of free glycerol present in the sample. This is achieved by running a blank. 

The carbon-water-glycerol ink is printed onto the PTFE blank. 

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