US3814255A

US3814255A - Triglyceride cholesterol analysis

Info

Publication number: US3814255A
Application number: US00270668A
Authority: US
Inventors: R Smernoff
Original assignee: ANALYTICAL PROD
Current assignee: ANALYTICAL PROD; ANALYTICAL PROD INC US
Priority date: 1972-07-11
Filing date: 1972-07-11
Publication date: 1974-06-04
Anticipated expiration: 1991-06-04

Abstract

The invention is concerned with a process for preparing a liquid sample for triglyceride and cholesterol analysis and the subsequent analysis of the sample thus prepared. The sample is prepared from a plasma- or a serum-lipid solvent composition. The preferred solvent is isopropyl alcohol. The cholesterol and triglyceride, along with most of the solvent, are separated from the composition by flowing the composition through a column comprising activated porous inorganic oxide particles. The activated particles are most preferably alumina, must have no more than a limited amount of fines, and principally fall within a 15 to 200 mesh size.

Description

United States Patent [191 Smernoff [11] 3,814,255 June 4, 1974 TRIGLYCERIDE CHOLESTEROL ANALYSIS [75] Inventor: Ronald B. Smernoff, Belmont, Calif.

[73] Assignee: Analytical Products, Inc., San

Carlos, Calif.

[22] Filed: July 11, 1972 [21] Appl. No.: 270,668

[52] US. Cl 210/31 C [51] Int. Cl B01d 15/08 [58] ,Field of Search 210/31 C, 298 C; 55/67,

Isolation of Carcinoliain by Combined Liquid-Solidand Liquid-Solid Chromatography, by Hradec et al.

Primary Examiner.lohn Adee Attorney, Agent, or Firm-Moore, Zimmerman &

Dubb

' [57] ABSTRACT The invention is concerned with a process for preparing a liquid sample for triglyceride and cholesterol analysis and the subsequent analysis of the sample thus prepared. The sample is prepared from a plasmaor a serum-lipid solvent composition. The preferred solvent is isopropyl alcohol. The cholesterol and triglyceride, along with most of the solvent, are separatedfrom the composition by flowing the composition through a column comprising activated porous inorganic oxide particles. The activated particles are most preferably alumina, must have no more'than a limited amount of fines, and principally fall within a 15 to 200 mesh size.

19 Claims, No Drawings 1 Y TRIGLYCERIDE CHOLESTEROL ANALYSIS BACKGROUND OF THEINVENTION The invention is concerned with a novel and advantageous method for preparing liquid samples for triglyceride and cholesterol analysis from plasmaor serumlipid'solvent compositions and a process for analyzing the liquid samples. Triglyceride and cholesterol analysis is important for detecting hyperlipoproteinemia.

The largest single cause of mortality in Western civilization is cardiovascular disease. Coronary heart diseases such as atherosclerosis and the like are contributhat, inter alia, lipid metabolism disorders are correlatable conditions to the occurance of coronary heart disease including atherosclerosis. In particular, elevated levels of triglyceride and/or cholesterol are well known to be frequently associated with atherosclerosis. Present theories point to a probable genetic origin of these disorders which are believed to be manifestations and phenotypes of errors of lipid transport within particular individuals. Frederickson et al. in N. Eng]. Med. Vol.

276 (1967) has analyzed the different types of disorders as hyperlipoproteinemia.

Analysis of cholesterol and triglyceride levels can be used to determine the different types of hyperlipoproteinemia (Harlan, Arch. lntern. Med. Vol. 124, July 1969). For preliminary screening of large populations for hyperlipoproteinemia the measurement of plasma triglyceride and plasma cholesterol levels and visual specimen inspection for each individual is all that is necessary. Further testing may of course be indicated with individuals who exhibit high cholesterol levels, triglyceride levels or both. From the above discussion, it can be seen that there is a very real need for an inexpensive, reliable, and most especially a rapid'method of detecting hyperlipoproteinemia.

PRIOR ART The prior art discloses three major methods for preparing liquid samples for triglyceride and/or choles-- terol analysis. In the first method, that of L. A. Carlson and L. E. Wadstrom, Clinica Chemica Acta, Volume 4, page 197 I959) a silicic acid column is used to adsorb neutral steroids, cholesterol, and triglyceride. The triglyceride is then selectively desorbed from the column.

in the second prior art method, aplasmaor serumlipid solvent composition is mixed vigorously with an activated zeolite, diatomaceous earth, lime, and copper sulfate. After agitation, the resulting mixture is centrifuged and thereafter the supernatent liquid is carefully to be obtained. A further problem with this second prior art method is that zeolites tend to lose activation in a relatively short time. Thus, the zeolite must be relatively freshly activated.

The third prior art method is set out in US. Pat. No. 3,645,688 issued Feb. 29, 1972. The process proceeds as does the second method set out above but uses activated alumina in place of activated zeolite. The activated alumina l retains its activation through a much longer period of time than does a zeolite and (2) sediments out better than a zeolite since alumina has a less fluffy nature. The method set out in US. Pat. No. 3,645,688, however, is relatively time consuming as compared to the method of the present invention, still requires considerable operator skill in removing the supernatent liquid (by careful pipetting) after the centrifuging step, and can also give high results due to heating up of the centrifuge tubes along with a concom- 'mitant evaporation of the lipid solvent. Thus, it would be highly desirable to have a process for preparing a liquid sample for triglyceride and cholesterol analysis which l is faster than prior art methods, (2) does not require a great deal of skill on the part of the operator performing the process, and (3) does not give high analysis results because of centrifuging heat up.

Accordingly, it is an object of the present invention to provide a more rapid and reproducible process for preparing a liquid sample for triglyceride and cholesterol analysis.

A further object of the invention is to provide a process for preparing a liquid sample suitable for triglyceride and cholesterol analysis which is relatively independant of the skill of the operator performing said process.

A still further object of the invention is to provide a process for preparing a liquid sample suitable for triglyceride and cholesterol analysis wherein it is not necessary or even particularly desirable to make use of lime, diatomaceous earth, or copper sulfate.

Another object of the invention is to provide a process capable of accomplishing the above set out objects, the liquid sample obtained therefrom yielding more accurate triglyceride and/or cholesterol analysis results. 7

Yet another objectof the invention is to provide a more rapid and more accurate process for determining triglyceride and/or cholesterol.

SUMMARY OF THE INVENTION The invention, in the broad sense, comprises a process for preparing a liquid sample for triglyceride and cholesterol analysis from a plasmaor a serum-lipid so]- vent composition. The process comprises separating triglyceride and cholesterol dissolved in the lipid solvent, from a plasma or'a serum-lipid solvent composition by flowing the composition through activated porousinorganic oxide particles. The particles must contain less than about 5 percent by weight of particles fine enough to pass through a 350 mesh seive and must be a least 98 percent by weight 15 to 200 mesh in size.

GENERAL DESCRIPTION OF THE lNVENTlON I As has been stated above, the process of the present invention may be used on any sample containing triglyceride and/or cholesterol. Plasma or serum may be used as a starting material. Similarly, biological specimens, tissue, and the like, may be used as the starting material. In any event, the starting material, which for convenience sake is referred to herein as a plasma or a serum, must be combined with a lipid solvent to form an overall plasmaor a serum-lipid solvent composition. It is preferred that fasting-state plasma or serum be used.

The lipid solvent serves to coagulate any proteins present for trapping above the activated porous inorganic oxide column and to dissolve lipids, some of which, particularly triglyceride and cholesterol, pass through the column and the remainder of which, along with glucose and peptides, are retained on the column. The preferred lipid solvent is isopropyl alcohol. There are however a number of other lipid solvents which may be used including, for example, chloroform, methanol, hexane, nonane, petroleum ether, and the like. lsopropyl alcohol is the preferred lipid solvent since the other solvents named above have not been found to be as effective as the isopropyl alcohol for dissolving cholesterol and triglyceride. I

As stated above, the separation of the triglyceride and cholesterol containing eluate from the plasmaor serum-liquid solvent composition is accomplished by flowing the composition through a column comprising porous inorganic oxide particles. Suitable inorganic oxides would have a high surface area, for example, from about 50 to about 700 m /gm, more preferably from about 100 to about 400 m /gm. The inorganic oxide can be a natural or a synthetically produced inorganic oxide or a combination of inorganic oxides. Typical inorganic oxides which can be used are the naturally occuring aluminum silicates and synthetically produced inorganic oxides such as silica-alumina, silica-zirconia,.

silica-alumina-zirconia, silica-magnesia, silica-aluminamagnesia, zeolites, magnesia and alumina.

Preferred for the purposes of the present invention are alumina and zeolites and in particular alumina.

The porous inorganic oxide particles of the present invention are activated as by heating for a sufficient period of time and at a sufficient temperature to significantly reduce their moisture content. The preferred alumina of the present invention is Alcoa (Trademark of Aluminum Company of America) F-l activated alumina. This material is capable of absorbing moisture to 14-16 percent of its dry weight at 60 percent relative humidity. A detailed description of Alcoa F-l activated alumina appeared in Alcoa Product Data Chemicals Activated Alumina and Catalytic Aluminas' July 14, 1969 published by Aluminum Company of America, Pittsburgh, Pa. l52l9.

The particle size of the porous inorganic oxide is important. The particles should be nominally at least 98 percent by weight 15 to 200 mesh in size. More prefer-- rably, the particles are nominally at least 98 percent by weight 15 to l 50 mesh in size. Still more preferably, the particles should be nominally at least 98 percent by weight l5 to 50 mesh in size. The most preferred material contains particles at least 98 percent by weight 28 to 48 mesh. The term nominally is used because commercial materials are often sold as being x to y mesh while they still may contain several percent of finer particles.

The amount of fines in the porous solid inorganic oxide is alsoimportant. Commercially available products such as the preferred Alcoa F-l activated alumina generally contain 3 percent to 7 percent by weight of particles fine enough to pass through a 350 mesh seive.

It has been found that porous inorganic oxide particles with this large an amount of fines particles which will pass through a 350 mesh seive) are usable in practicing the present invention but are inferior to similar inorganic oxide particles with less fines in that some of the fines will pass through the column of solid inorganic oxide particles and thereafter can interfere with analysis for triglyceride and/or cholesterol to give falsely elevated results. Thus, it has been found most advantageous to employ a porous solid inorganic oxide which contains less than 3 percent, more preferably less than about 2 percent, and most preferably less than about 1 percent, said percents being by weight, of particles fine enough to pass through a 350 mesh seive. Such a material can be obtained by seiving of commercially available porous inorganic oxides particles such as the preferred 28-48 mesh activated alumina, Alcoa F-l.

The plasmaor serum-lipid solvent composition generally comprises a cloudy or milky appearing suspension of coagulated proteinaceous material in combination with dissolved peptides, dissolved glucose, and dissolved triglyceride and cholesterol. According to the process of the present invention a liquid sample containing the triglyceride and cholesterol but not containing the proteinaceous material is separated from the composition by flowing the composition through a column comprising porous inorganic oxide particles. The flowing is a very simple and straightforward operation in practice. In general, the composition is simply poured .into a suitable space atop the column of the solid inorganic oxide particles and allowed to flow downwardly under the influence of natural gravity, the coagulated material being maintained atop the column. The eluate from the bottom of the column then contains the dissolved triglyceride and cholesterol and is free of interfering substances.

By interfering substances, I mean substances which might cause an analysis for cholesterol and/or triglyceride to be incorrect. It is a very positive advantage of the process of the present invention that when the porous solid inorganic oxide material is alumina it is unnecessary to add lime, copper sulfate, diatomaceous earth, or

' other materials thereto to aid in the separation. It is of course possible to add these materials if desired but b'asically they do no good since the process of the present invention provides a liquid sample which is suitable without further processing for triglyceride and cholesterol analysis. Thus, porous inorganic oxide particles having the characteristics described herein and consisting essentially of activated alumnia are sufficient for successfully carrying out the process of the present invention..

It is preferred to flow the eluate from the column of activated porous solid inorganic oxide particles through an inert filter pad having a porosity which falls within the range from about to about 300 cubic feet of air per square foot of surface per minute at an air flow pressure of 5 inches of water. More preferably, the porosity of the inert filter pad fallswithin the range from about 80 to about 200 cubic feet of air per square feet of surface area per minute at an air flow pressure of 5 inches of water and still more preferably a porosity in the range from'about to about cubic feet of air per'square foot of surface per minute at an air flow pressure of 5 inches of water. When the filter pad is spoken of as inert it is meant that the material of the filter pad will not react withtriglyceride or cholesterol thereby adversely affecting the accuracy of a'later analysis for these components. Any material which satisfies this criterion for inertness is useable. It has been found, for example, that a rayon filter pad is quite suitable.

As has been previously pointed out, what occurs on the activated porous inorganic oxide particles is at least a partial chromatographic separation of the interfering dissolved materials including the peptides, phospholipids, bilirubin and glucose present, along the length of the column, all of which materials are retained on the column in chromatographic zones of the column. The triglyceride and cholesterol, which are not retained by the column, pass'through said column and'flow out the bottom thereof along with most of the lipid solvent to provide a liquid sample suitable for triglyceride and cholesterol analysis.

Methods for preparing the original plasmaor serumlipid solvent composition are so well known as to not require any detailed discussion herein. In brief, the plasma and/or serum is combined with the lipid solvent to produce the desired composition. This will serve to coagulate the majority of the proteinaceous material while the lipids and other lipid solvent soluble material including triglyceride and cholesterol remain dissolved in the liquid portion of the composition.

Analysis of the liquid sample for triglyceride and/or cholesterol content is also so well known as to not need an extensive description herein. Briefly, the triglyceride determination is a conventional colorimetric detennination involving a comparison between Blank, Standard, and Unknown samples. The Blank sample is the liquid solvent, generally isopropanol. The standard samples are preferably prepared using triolein triglyceride. Generally a plurality of standards is used so that it is possible to plot a standard curve of optical'density against concentration. The Unknown is of course the liquid sample prepared by the method of the present invention.

The Standard and Unknown samples are treated identically in that the triglyceride is saponified to glycerol using for example, potassium hydroxide. Heating a Sample-potassium hydroxide composition for about 5 minutes at about 60 to 70C. is generally sufficient for accomplishing the saponification.

The saponified glycerol is then oxidized using a mild 0 dard, and Unknown samples are prepared. The Blank sample consists of the lipid solvent, usually isopropyl ferric chloride dissolved in acetic acid. The importantreaction is that of ferric ion with chloresterol' in the presence of acetic acid and a sulfuric acid catalyst to give a violet product. The intensity of the violet color is then measured colorimetrically. Generally the reaction with the ferric ion will be accelerated by use of a 60C. to 70C. heating of the sample for about 5 min utes. Optical density is measured at 560m against the reagent Blank. A standard curve is prepared in the usual manner (as with the triglyceride determination) and the concentration of cholesterol in the unknown is determined by comparison with the standard curve.

More detailed descriptions of the triclyceride and cholesterol analysis techniques may be found in the aforementioned US. Pat. No. 3,645,688.

. DETAILED DESCRIPTION OF THE PREFERRED w, EMBQPWENT The process of the present invention is illustrated by the following preferred embodiment thereof.

A serum-isopropyl alcohol or more preferably a plasma-isopropyl alcohol composition has a liquid sample containing a triglyceride and cholesterol separated therefrom by flowing the composition through a column comprising activated alumina particles. The eluate from the column of activated alumina particles is preferably flowed through an inert filter pad having a porosity which falls within the range from about 80 to about 300 cubic feet of air per square foot of surface per minute at an air flow pressure of 5 inches of water.

' The column of activated alumina particles adsorb and at least partially chromatographically separate the various components of the original composition which would interfere with a later triglyceride and/or cholesterol analysis. The eluate from the column of activated oxidizing agent, preferably sodium metaperiodate. Formaldehyde' is a typical product of the oxidation. The formaldehyde may then be reacted with a beta diketone as described by Fletcher, Clin. Chim. Acta 22 (1968). When acetylacetone, which is the preferred beta diketone, is used the formaldehyde produced from the triglyceride reacts with the acetylacetone and a yellow dihydrolutidine derivative is formed which has an absorbance maximum at 405mg. After addition of the acetylacetone it is preferred to heat the samples for about 5 minutes at about 60C. to about 70C. The colorimetric testing proceeds using a standard colorimeter or spectrophotometer. Optical density is measured at 405m against the reagent Blank. Standard points are established for this spectrophotometer at appropriate concentrations of triglyceride, for example, within the range from about 75 mg to about 300 mg percent triglyceride.

Cholesterol, analysis may also proceed by very well known means on liquid samples produced by the process of the'present invention. Once again Blank, Stanthereby.

alumina particles is suitable without further processing for triglyceride and cholesterol analysis. It has been found convenient to use a plastic throw-away tube to hold the column of activatedalumina particles. A convenient size for the tube is 7 millimeters in diameter by 5 centimeters in length. Generally the tube will containabout 2 grams of activated alumina particles. The tube will also generally have sufficient space left above the alumina particles to accept the entire plasma-isopropyl alcohol composition, usually about 5 to 6 cc.

A suitable inert filter pad is preferably positioned beneath the alumina column and the eluate from the alumina column is flowed therethrough. It has been found that rayon of appropriate porosity makes an. excellent filter pad and it is believed that the separation attained as a result of the use of the column of activated alumina particles is improved still further when an inert filter pad is present.

The process and advantages of the present invention would be better understood by reference to the examples which follow. The examples are meant to be illustrative'only and it is of course understood that the invention is not to be considered as being limited EXAMPLES 1. Example 1 Each of four 5.3ml aliquots from a supply of pure .isopropyl alcohol was individually mixed with 2.5gm of Alcoa F-l activated alumina of 48-100 mesh in size. The activated alumina was used directly out of the bag as supplied by the seller thereof and contained within the range from 4 to 7 percent fines (particles which would pass through-a 350 mesh sieve.

After mixing, the resulting suspensions were individually centrifuged for about minutes. This is a very typical time. for centrifuging plasmaor serumisopropyl alcohol compositions after they have been mixed with activated alumina to settle out the solids suspended therein.

After centrifugation, the supernatant liquid was carefully and separately removed by pipette from three of the samples and placed in tubes-designated herein for convenience A, B, and C. The supernatant liquid from the fourth centrifuge tube was carefully decanted into a tube designated herein as D. v

Each of three other 5.3 ml aliquots from the same supply of pure isopropyl alcohol was individually flowed through columns containing 2.5gm each of Alcoa E-l activated alumina of 28-48 mesh size and then through a rayon filter pad having a porosity of 120 to 150 ft of air per ft of surface per minute at an air flow pressure of 5 inches of water. The activated alumina was first sieved so that it contained less than 1 percent fines. The three eluates were kept separate and were placed in tubes designated herein E, F, and G.

The optical absorbance of the isopropyl alcohol contained in tubes A, B, C, D, E, F, and G was then measured at 405mp. as compared against the optical absorbance of a blank sample of pure isopropyl alcohol taken directly from the same supply of pure isopropyl alcohol. Triglyceride is normally measured at 405mg. The results obtained are tabulated infra:

Tube Designation Measured Ahsorbance 0.08 Y Substantially Opaque Elevated absorbance was observed for each of the samples treated by the mixing; centrifuging, and decanting or pipetting method (A, B, C, and D). Elevated ahsorbance was not observed for any of the samples treated by the flowing through column method.

This example demonstrates the excellent, improved, and highly reproducible sample preparation method of the present invention. In addition, it is shown that perhaps the best of the prior art methods of sample preparation can give high results.

2. Example 2 Aliquots of six different serum samples were obtained from a hospital laboratory. Each of the six aliquots was individually analyzed for triglyceride by the method of the present invention, the aliquots each being prepared for triglyceride analysis by the method given in Example 1 for samples E, F, and G. The triglyceride levels of each of the six aliquots, hereafter designated H, l, J. K, L, and M, was measured colorimet cal y 0m1 Identical aliquots of the same six different serum samples were analyzed by the hospital laboratory. Each of the six aliquots analyzed by the hospital laboratory was converted into a liquid sample for triglyceride anal-v ysis by the method given in Example 1 for samples A, B, and C. The triglyceride levels of each of the six aliquots, hereafter designated H, l, J, K, L, and M, was measured colorimetrically at 405mg.

The results of the above 12 analysis are given in the following table:

This example demonstrates the good agreement of the rapid method of the present invention with the relatively slow method of the prior art. The one disagreement in triglyceride levels noted (Samples H and H) is unexplained but is presumed to be due to an error in handling, probably at the hospital laboratory. It should be noted that normal triglyceride levels are generally within the range from 50 to l50mg/dl or 50 to ZOOmg/dl. Thus, the difference in Samples H and H would have no known medical significance.

The invention is hereby claimed as follows. While the foregoing specification describes the invention in great detail and in particular preferred embodiments thereof it is understood that the invention is limited only by the scope and spirit of the appended claims.

L claim:

1. A process for preparing a liquid sample for triglyceride orcholesterol analysis-from a plasmaor a serumlipid solvent composition, comprising:

Separating a liquid sample comprising triglyceride or cholesterol and a lipidsolvent from a plasmaor a serum-lipid solvent composition by flowing the composition through a column comprising activated porous inorganic oxide particles, said particles:

l. containing less than about 5 percent by weight of particles fine enough to pass through a. 350 mesh seive; and

2. being nominally at least 98 mesh to 200 mesh in size.

2. A process as in claim 1. wherein the flowing comprises flowing substantially downwardly under the influence of natural gravity.

3. A process as in claim 1, including as an added step:

percent by weight 15 flowing the eluate from the column of activated porous solid inorganic oxide particles through an inert filter pad having a porosity which falls within the range from about'80 to about 300 cubic feet of air per square foot of surface per minute at an air flow pressure of 5 inches of water.

4. A process as in claim 3 wherein said porosity falls within the range from about to about 200 cubic feet of air per square foot of surface per minute at an air flow pressure of 5 inches of water.

a 5.1 A process as in Claim 1 further characterized in weight of particles fine enough to pass through a 350 mesh seive.

6. A process as in claim 1 further characterized in that the particles contain less than about 1 percent by weight of particles fine enough to pass through a 350 mesh seive.

7. A process as in claim 1, wherein the particles are nominally at least 98 percent by weight 28 mesh to 48 mesh in size.

8. A process as in claim 1 wherein said porous solid inorganic oxide is selected from the group consisting of an alumina and a zeolite.

9. A process as in claim 8 wherein said porous inorganic oxide comprises a zeolite.

10. A process as in claim 8 wherein said porous inorganic oxide comprises an alumina.

11. A process as in claim 1 wherein said porous inorganic oxide consists essentially of alumina.

12. A process for preparing a liquid sample having dissolved therein triglyceride or cholesterol from a plasmaor a serum-lipid solvent composition, comprismg:

separating a liquid sample comprising triglyceride or cholesterol dissolved in a lipid solvent from a plasmaor a serum-lipid solvent composition by flowing the. composition substantially downwardly under the influence of gravity through a column comprising activated alumina particles, said activated alumina having a surface area within the 14. A process as in claim 13, wherein the particles contain less than about 1 percent by weight of fine particles.

15. A process as in claim 14, wherein the particles are nominally at least 98 percent by weight 28 to 48 mesh.

16. A process as in claim 15, including as an added Step:

flowing the eluate from the column through an inert filter pad having a porosity within the range from about to about 300 cubic feet of air per square foot of surface per minute at an air flow pressure of 5 inches of water.

17. A process for determining triglyceride or cholesterol for the detection of hyperlipoproteinemia, comprising:

l. combining serum or plasma with a lipid solvent.

2. separating a sample comprising triglyceride or cholesterol dissolved in the lipid solvent from the composition resulting from step l by flowing the composition through a column comprising activated porous inorganic oxide particles, said particles:

a. containing less than about 5 percent by weight of fine particles said fine particles being passable through a 350 mesh seive; and g b. being nominally at least 98 percent by weight 15 mesh to 200 mesh in size; and

3, analyzing the sample for triglyceride or cholesterol.

18. A process as in claim 17, wherein the inorganic oxide comprises alumina containing less than about 3 percent by weight of fine particles and the particles are nominally at least 98 percent by weight l5 mesh to 50 mesh in size.

19. A process as in claim 18, wherein the alumina contains less than about 2 percent by weight of fine particles.

Claims

2. being nominally at least 98 percent by weight 15 mesh to 200 mesh in size.
2. A process as in claim 1 wherein the flowing comprises flowing substantially downwardly under the influence of natural gravity.
2. separating a sample comprising triglyceride or cholesterol dissolved in the lipid solvent from the composition resulting from step (1) by flowing the composition through a column comprising activated porous inorganic oxide particles, said particles: a. containing less than about 5 percent by weight of fine particles said fine particles being passable through a 350 mesh seive; and b. being nominally at least 98 percent by weight 15 mesh to 200 mesh in size; and
2. being nominally at least 98 percent by weight 15 mesh to 50 mesh in size.
3. A process as in claim 1, including as an added step: flowing the eluate from the column of activated porous solid inorganic oxide particles through an inert filter pad having a porosity which falls within the range from about 80 to about 300 cubic feet of air per square foot of surface per minute at an air flow pressure of 5 inches of water.
3. analyzing the sample for triglyceride or cholesterol.
4. A process as in claim 3 wherein said porosity falls within the range from about 80 to about 200 cubic feet of air per square foot of surface per minute at an air flow pressure of 5 inches of water.
5. A process as in claim 1 further characterized in that the particles contain less than about 2 percent by weight of particles fine enough to pass through a 350 mesh seive.
6. A process as in claim 1 further characterized in that the particles contain less than about 1 percent by weight of particles fine enough to pass through a 350 mesh seive.
7. A process as in claim 1, wherein the particles are nominally at least 98 percent by weight 28 mesh to 48 mesh in size.
8. A process as in claim 1 wherein said porous solid inorganic oxide is selected from the group consisting of an alumina and a zeolite.
9. A process as in claim 8 wherein said porous inorganic oxide comprises a zeolite.
10. A process as in claim 8 wherein said porous inorganic oxide comprises an alumina.
11. A process as in claim 1 wherein said porous inorganic oxide consists essentially of alumina.
12. A process for preparing a liquid sample having dissolved therein triglyceride or cholesterol from a plasma- or a serum-lipid solvent composition, comprising: separating a liquid sample comprising triglyceride or cholesterol dissolved in a lipid solvent from a plasma- or a serum-lipid solvent composition by flowing the composition substantially downwardly under the influence of gravity through a column comprising activated alumina particles, said activated alumina having a surface area within the range from about 50m2/gm to about 750m2/gm, said particles:
13. A process as in claim 12, wherein the alumina has a surface area within the range from about 100m2/gm to about 400m2/gm and the particles contain less than about 2 percent by weight of fine particles.
14. A process as in claim 13, wherein the particles contain less than about 1 percent by weight of fine particles.
15. A process as in claim 14, wherein the particles are nominally at least 98 percent by weight 28 to 48 mesh.
16. A process as in claim 15, including as an added Step: flowing the eluate from the column through an inert filter pad having a porosity within the range from about 80 to about 300 cubic feet of air per square foot of surface per minute at an air flow pressure of 5 inches of water.
17. A process for determining triglyceride or cholesterol for the detection of hyperlipoproteinemia, comprising:
18. A process as in claim 17, wherein the inorganic oxide comprises alumina containing less than about 3 percent by weight of fine particles and the particles are nominally at least 98 percent by weight 15 mesh to 50 mesh in size.
19. A process as in claim 18, wherein the alumina contains less than about 2 percent by weight of fine particles.