Oxalate, Plasma

Table 3.5.3 Reference values for urinary oxalate, glycolate, citrate, glycerate (given in mmol/mol creatinine), and sulfate (given in mol/mol creatinine), and plasma oxalate, citrate, and sulfate (given in fimol/l)...

Human blood plasma Oxalic acid Calcium chloride Ammonium sulfate... 

Sample material Serum, heparin plasma, EDTA plasma, oxalate plasma, fluoride plasma, fluoride-oxalate plasma or iodacetate plasma. 

Petrarulo M, CereUi E, Marangella M, Cosseddu D, Vitale C, Linari F. Assay of plasma oxalate with soluble oxalate oxidase. Clin Chem 1994 40 2030-4. 

Zl. Zarembski, P. M., Hodgkinson, A., and Parsons, F. M., Elevation of the concentration of plasma oxalic acid in renal failure. Nature (London) 212, 511-512 (1966). 

Preparation of the sample. Either semm or plasma (oxalated or heparinized) may be used for the determination. This may be freshly drawn blood from an animal. (Do not do this yourself your instructor will supply the sample.) See Chapter 1 for a discussion of the differences between semm, plasma, and whole blood. A 10- to 15-mL sample (20 to 30 mL whole blood) should be adequate for triplicate determinations by a class of 30 students. Fluoride should be added to prevent glycolysis, or breakdown of glucose, which can change the pH. The fluoride inhibits the enzyme catalysis causing glycolysis and stabilizes the pH for about 2 h. The tube used for collecting the sample can be rinsed with a solution of 100 mg sodium heparin plus 4 g sodium fluoride per 100 mL. The sample should be kept anaerobically, that is, stoppered to keep out atmospheric CO2. Since the analysis should be done on the day the blood is drawn, the solutions should be prepared ahead of time. 

Devi, R., Relhan, S., and Pundir, C. S. [2013]. Construction of a chitosan/ polyaniline/graphene oxide nanoparticles/polypyrrole/Au electrode for amperometric determination of urinary/plasma oxalate. Sens. Actuators, B, 186, pp. 17-26. 

Fig. 26.2. Differential diagnosis of hyperoxalurias. UOx, urinary oxalate POx, plasma oxalate PP, renal failure CAPDy continuous ambulatory peritoneal dialysis pre-HDy prehemodialysis AGTy alanine glyoxylate aminotransferase GP, glyoxylate reductase...

Electrolytes, uric acid, creatinine, urea. Mg, P04, plasma oxalate, acid base status, AP... 

Slightly elevated urinary oxalate excretion and plasma oxalate levels in patients may indicate another not yet well-defined form of primary hyperoxaluria (type III ) (Monico and Milliner 1999 Rose 1988). Patients have severe recurrent urolithiasis, but may respond even to low doses of pyridoxine (Edwards and Rose 1991 Hoppe et al. 2007). 

From oxalate added blood plasma by precipitation with CaClj and purification by washing and precipitation and lyophilization. 

Because process mixtures are complex, specialized detectors may substitute for separation efficiency. One specialized detector is the array amperometric detector, which allows selective detection of electrochemically active compounds.23 Electrochemical array detectors are discussed in greater detail in Chapter 5. Many pharmaceutical compounds are chiral, so a detector capable of determining optical purity would be extremely useful in monitoring synthetic reactions. A double-beam circular dichroism detector using a laser as the source was used for the selective detection of chiral cobalt compounds.24 The double-beam, single-source construction reduces the limitations of flicker noise. Chemiluminescence of an ozonized mixture was used as the principle for a sulfur-selective detector used to analyze pesticides, proteins, and blood thiols from rat plasma.25 Chemiluminescence using bis (2,4, 6-trichlorophenyl) oxalate was used for the selective detection of catalytically reduced nitrated polycyclic aromatic hydrocarbons from diesel exhaust.26... 

P-Carboline alkaloids (harmaline, har-malol, harmane, harmol, harmine) 0.3-150 0.25-90 2.9-3.1 Harmaline was determined in plasma samples DNPO was used as aryl oxalate 45... 

Since the order of increasing CL intensity for alkyl amines reacted with Ru(bpy)32+ is tertiary amines > secondary amines > primary amines, pharmaceutical compounds bearing a tertiary amine function (e.g., antihistamine drugs [99], anticholinergic drugs [100], erythromycin [101], and its derivatives [102]) have been sensitively determined after HPLC separation (Table 3). The method was applied to the detection of d- and L-tryptophan (Trp) after separation by a ligand-exchange HPLC [103], The detection limits for d- and L-Trp were both 0.2 pmol per injection. Oxalate in urine and blood plasma samples has also been determined by a reversed-phase ion-pair HPLC (Fig. 18) [104], Direct addition of... 

Figure 18 Chromatogram of oxalate in blood plasma. Peaks A = amino acids B = oxalate. (From Ref. 104.)...

Since part of the inositol occurs in blood plasma in conjugated form, the sample must be hydrolyzed. This serves at the same time for depro-teinization. Ten milliliters of oxalated plasma obtained in the fasting state are hydrolyzed with 100 ml of 18% HC1 for 6 hours and the hydro-... 

Oxalate does not interfere with glucose assays, but insulin values determined in oxalate-plasma are lower than those obtained with lithium heparin-plasma or serum (L6). Specimens collected in EDTA demonstrate lower carbon dioxide combining power than those observed with serum or heparin or potassium oxalate plasma (Zl). 

Enzymes activities are particularly sensitive to the anticoagulant used in collecting the specimen. Heparin inhibits acid phosphatase (W16) and muramidase (Z5). Amylase activity is inhibited by oxalate or citrate (MIO), and lactic dehydrogenase and acid phosphatase lose activity in oxalate (C2). Alkaline phosphatase is stable in oxalate, oxalate-fluoride, or heparin, but 25 mAf citrate inhibits 50% of the activity, and as little as 50 mlf EDTA is completely inhibitory (B19). Leucine aminopeptidase is inhibited by EDTA, as is creatine phosphokinase (F3). Amylase activity has been reported to be only 83% of that in serum when oxalate or citrate-plasma is used (MIO). Heparin plasma appears to have no inhibitory effect. Despite the fact that clotting factor V is not stable in oxalate or EDTA, these are often used as anticoagulants to obtain plasma for prothrombin determinations (Z2, Z4). 

Lactate and can be measured in plasma. Blood is collected in a tube with an anticoagulant (heparin, EDTA, oxalate) and antiglycolytic agent (fluoride - without which there is an artefactual increase in lactate levels). The tube is transported in ice water and plasma is separated from the blood within 15 min following sampling. 

Standard mixture II for plasma 10 gM oxalate, 20 gM glycolate, 20 gM sulfate, 20 gM citrate. Dilute 200 gl of the standard mixture I with 800 gl of 0.3 M boric acid. Prepare fresh before running the assay. 

Hoppe B, Kemper MJ, Hvizd MG, Sailer DE, Langman CB. (1998) Simultaneous determination of oxalate, citrate and sulfate in childrens plasma with ion chromatography. Kidney Int 53 1348-1352... 

Substances Thrombin time of oxalate filled plasma, (s) The lysis time (h) at 37 °C of a clot produced from ... 

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