Alkalinity reference values

Alkalinity and Lime Content. Alkalinity is the ability of a solution or mixture to react with an acid. The phenolphthalein alkalinity refers to the amount of acid required to reduce the pH to 8.3, the phenolphthalein endpoint. The phenolphthalein alkalinity of the mud and mud filtrate is called the and Pp respectively. The P. test includes the effect of only dissolved bases and salts while the P test includes the effect of both dissolved and suspended bases and salts. The methyl orange alkalinity refers to the amount of acid required to reduce the pH to 4.3, the methyl orange endpoint. The methyl orange alkalinity of the mud and mud filtrate is called the and Mp respectively. The API diagnostic tests include the determination of P, Pp and Mp All values are reported in cubic centimeters of 0.02 N (normality = 0.02) sulfuric acid per cubic centimeter of sample. 

I have made some changes in GRAFINIT to provide more generally informative real-time plots. The reference value for atmospheric carbon dioxide is set to 1 PAL, so that with a sensitivity of 0.2,1 look at departures from 1. As before, the reference values for alkalinity and dissolved carbon are the starting values. For the isotopes I plot departures of delta from 0, with a sensitivity of 1 for 13C and 100 for 14C. 

Stinton TJ, Crowley D, Bryant SJ. Reference values of calcium, phosphate, and alkaline phosphatase as derived on the basis of multi-analyzer profiles. Clin Chem 1986 32 76-9. 

Ladenson et al. (LI), Breuer and Stucky (B43) and Fleisher et al. (F13) demonstrated that identical values are obtained with heparinized plasma and serum. Lum and Gambino (L20) found lower mean values in heparinized plasma than in serum but the differences were small. On the other hand, EDTA causes an irreversible inactivation of several human alkaline phosphatases (C27) and is not suitable as an anticoagulant for biological fluids if alkaline phosphatase measurements are to be made (Mc3). In this review, we shall refer to serum alkaline phosphatase values even if the actual measurements were made on plasma. 

In spite of the skewed distribution of serum alkaline phosphatase values, many authors continue to speak in terms of means and 2 standard deviations even though such cut-off points do not identify the central 95% of observed values. Elveback et al. (ElO) therefore suggested that the upper and lower reference limits be set at 2 and 97y centiles above and below the median value. This is standard practice in expressing other biological values, such as the height of growing children. 

Fig. 2. Plasma alkaline phosphatase values in children and adolescents plotted as moving geometric means. Each mean is based on data from 80 children. The next mean is based on data from the 30 oldest of these 80, plus the next 50 in order of age. The solid circles denote males, the open circles females. The upper reference limit for adults obtained by the method employed was 256 U/liter. Note that the peripubertal rise occurs later in boys and is more pronounced than in girls. From Fleisher et al. (F13) with permission.

Fig. 3. Means and observed ranges of serum alkaline phosphatase values during childhood and adolescence in males. The upper reference limit for adults is 3 Bessey-Lowry-Brook units/milliliter. Note the wide observed range and the persistence of high values in some individuals. Data from Clark and Beck (C22) with permission.

However, there is only an indirect correlation between bone resorption and serum alkaline phosphatase activity. Patients with predominantly lytic lesions of the skeleton, as in multiple myeloma, have alkaline phosphatase values that are within reference limits or are only slightly elevated (S17). In addition, no correlation has been demonstrated between serum alkaline phosphatase and bone accretion rates as measured by bone-seeking isotopes (S36), which has prompted the suggestion that elevated serum alkaline phosphatase values in skeletal disorders might reflect the formation of bone matrix rather than bone (S36). 

The majority of patients with primary hyperparathyroidism have normal serum alkaline phosphatase values (Table 8). This test is therefore of little diagnostic significance. Serum alkaline phosphatase activities greater than twice the upper reference limit tend to be associated with radiological (D8, Ul) and histological (P36) evidence of parathyroid osteopathy. The converse is not true Histological examination of skeletal biopsy material may reveal bony lesions even when serum alkaline phosphatase values are within reference limits (P36). 

In recent years, several reports have appeared, particularly from Britain, concerning vitamin D-responsive osteomalacia due to nutritional causes (C29, H16, S76, W27). Most of the patients described were immigrants from India or Pakistan whose diet contained a high content of phytic acid (W27). Serum alkaline phosphatase activities in these patients ranged from normal to 20 times the upper reference limit for adults. After the commencement of therapy, activities fell to half the mean pretreatment values within approximately 4 months (C30, S76), although in some patients, this fall was difficult to distinguish from that normally seen in the peripubertal period (C29). In patients with very high serum alkaline phosphatase values, vitamin D therapy produced more spectacular reductions than in patients with mild elevations (H16, S76). 

End-stage renal failure is associated with histological skeletal lesions in 75-80% of patients (16). Fewer than 10% have serum alkaline phosphatase values in excess of 1.5 times the upper reference limit (16). 

Skeletal disease is common in patients with renal failure treated by chronic dialysis. The majority of these patients have histologically demonstrable bone disease, even in the absence of clinical symptoms (B21). However, serum alkaline phosphatase activities are either within reference limits or only moderately elevated (B21), with spectacular elevations occurring only rarely in both adults (B21, KIO) and children (P34). High serum alkaline phosphatase values have been described in patients on chronic dialysis with severe hypophosphatemic osteomalacia (M3). 

Viral Hepatitis B. Serum alkaline phosphatase values in patients with serum hepatitis are similar to those seen in patients with acute infectious hepatitis (K19). In the majority of cases, they are less than 3 times the upper reference limit (K19). 

Brucellosis. Hepatic granulomas are common in patients with brucellosis due to Brucella abortus (J6, Y4). Increases in serum alkaline phosphatase occur much less commonly. Joske and Finckh 07) found minor elevations in three out of five patients, although one of these probably had unrelated chronic active hepatitis. Buchanan et al. (B51) found hyperphosphatasemia in only one of the nine patients with brucellosis on whom they performed liver function tests. Young (Y4), who studied five patients suffering from Brucella melitensis hepatitis, found that none of them had serum alkaline phosphatase values in excess of one and a half times the upper reference value. 

Amebiasis. The majority of patients with hepatic amebiasis have serum alkaline phosphatase values within reference limits (L3). 

Even in patients with histologically proven alcoholic hepatitis, serum alkaline phosphatase may remain within reference limits. Green et al. (G21) found normal serum alkaline phosphatase values in 20 out of 46 patients with alcoholic hepatitis, while only 4 patients showed values greater than 2.5 times the upper reference limit. Bradus et al. (B39) described 83 patients whose liver biopsies showed fatty change but no evidence of cirrhosis. Mild increases in serum alkaline phosphatase (up to 2.5 times the upper reference limit) were found in about 50%. 

Cholestasis in the absence of demonstrable mechanical biliary obstruction is usually referred to as intrahepatic cholestasis, a term which implies that there is microscopic obstruction within the liver itself (P21). The condition occurs after the administration of various drugs, (see Table 10), in the presence of some infectious disorders (see Section 7.4), and during the last months of pregnancy. Mean serum alkaline phosphatase values in women with clinically overt cholestasis of pregnancy are higher than in matched controls (R13), although individual patients may have values appropriate to the last trimester of pregnancy (H2, R13). In some patients with intrahepatic cholestasis, no cause is identifiable (R35, S58). Serum alkaline phosphatase values in idiopathic cholestasis may be 7 times the upper reference limit (S75). 

Angiosarcoma of the liver is a rare tumor associated with previous exposure to vinyl chloride. Patients with such a tumor may have serum alkaline phosphatase values within the reference interval or many times the upper reference limit (FI). Makk et al. (M5) screened over 1000 apparently well workers at a polyvinyl chloride factory and found hyper-phosphatasemia in 32. In 15 of these cases, the circulating enzyme was predominantly of hepatic origin. Makk et al. (M5) stated that a relative elevation of liver functions could be detected in workers exposed to... 

Pack and Molander (PI) performed hepatic lobectomy in 23 patients suffering from tumors and allied diseases. Following surgery, serum alkaline phosphatase increased in the majority of patients, although prompt decreases occurred in several patients with extremely high preoperative levels. By the third week after surgery, 20 out of 33 patients had serum alkaline phosphatase values within reference limits. Decreases in serum alkaline phosphatase after hepatic resection were also observed by Almersjo et al. (A9). None of the 12 patients studied by Almersjo et al. (A9) showed a postoperative rise in serum alkaline phosphatase. Williams et al. (W23) reported massive falls in serum alkaline phosphatase values after liver transplantation. ... 

Serum alkaline phosphatase values in patients with this syndrome may lie within the reference interval or rise as high as 7 times the upper reference limit (C20, H19). Clain et al. (C20) were unable to demonstrate any correlation between serum alkaline phosphatase levels and serum bilirubin concentrations in this syndrome. 

Patients with uncomplicated cholelithiasis generally have serum alkaline phosphatase values within reference limits (S2, S51). For this reason, serum alkaline phosphatase elevation in patients with gallstones should raise the suspicion of a stone in the common bile duct (S2, S57) or some other hepatobiliary disorder. 

Bile peritonitis may be associated with varying degrees of hyper-phosphatasemia. Serum alkaline phosphatase values ranging from 1 to approximately 15 times the upper reference limit have been reported (13, Mc2, S57). The rise in serum alkaline phosphatase tends to lag behind the rise in serum bilirubin, the lag period varying from 2 to 14 days (Mc2). 

Gardner, M. D., and Scott, R., Frequency distribution and reference values of plasma alkaline phosphatase (EC 3.1.3.1) activity in the adult population of a Scottish new town. J. Clin. Pathol. 31, 1202-1206 (1978). 

Autoxidation of phenolic compounds may occur during extraction, particularly at alkaline pH values, but can be prevented, or at least limited, by extracting under oxygen-free nitrogen. It is advisable to treat reference compounds in a similar manner. After extraction with water, alkali or EDTA, extracts are acidified, usually to about pH 2.5, to convert the phenolics to the undissociated form. This enables them to be separated by partition into a suitable organic solvent (e.g. diethyl ether, ethyl acetate). In order to minimize the cis-trans isomerisation of the substituted... 

The first system, devised in the University of Porto, Portugal, was a sensor array for the measurement of creatinine in urine [18]. It consisted of a creatinine iminohydrolase enzyme immobilized by entrapment using a chitosan membrane onto a nonactin ISE. Catalytic hydrolysis by the enzyme generated ammonium ion which was then directly detected. The system was completed with ISEs for ammonium, potassium, sodium and calcium which allowed to correct for any endogenous ammonium (by the first ISE) or for alkaline and alkaline-earth interference in the ammonium-based biosensor (the other three). Linear response ranges were between 0.1 and 10 mM, what permitted the resolution of the multicomponent determination by PLS method. Comparison with reference Jaffe method showed a satisfactory correlation, although the slope of obtained vs. reference values was rather low the obtained value was 0.87, whereas theoretical value should be 1.0. 

Humic acids are alkaH-extractable materials and total humic acid content is a term that refers to the humic acid content of coal that has had its carboxylate cations removed with sodium pyrophosphate. Values for some typical AustraHan brown coals range from 24—92% (13). Treatment of lignitic coals with mineral acid to release the alkaH and alkaline cations may dissolve up to 20% of the coal. The naturally moist coals are slightly acidic and have a pH of 3.5—6.5. 

Taft began the LFER attack on steric effects as part of his separation of electronic and steric effects in aliphatic compounds, which is discussed in Section 7.3. For our present purposes we abstract from that treatment the portion relevant to aromatic substrates. Hammett p values for alkaline ester hydrolysis are in the range +2.2 to +2.8, whereas for acid ester hydrolysis p is close to zero (see Table 7-2). Taft, therefore, concluded that electronic effects of substituents are much greater in the alkaline than in the acid series and. in fact, that they are negligible in the acid series. This left the steric effect alone controlling relative reactivity in the acid series. A steric substituent constant was defined [by analogy with the definition of cr in Eq. (7-22)] by Eq. (7-43), where k is the rate constant for acid-catalyzed hydrolysis of an orr/to-substituted benzoate ester and k is the corresponding rate constant for the on/to-methyl ester note that CH3, not H, is the reference substituent. ... 

Because the ionic product of water = [H ] [OH ] = 1.04 x 10" at 25°C, it follows that pH = 14 - pOH. Thus, a neutral solution (e.g., pure water at 25°C) in which [H j = [OH ] has a pH = pOH = 7. Acids show a lower pH and bases a higher pH than this neutral value of 7. The hydrogen ion concentrations can cover a wide range, from -1 g-ion/liter or more in acidic solutions to -lO" " g-ion/liter or less in alkaline solutions [53, p. 545]. Buffer action refers to the property of a solution in resisting change of pH upon addition of an acid or a base. Buffer solutions usually consist of a mixture of a weak acid and its salt (conjugate base) or of a weak base and its salt (conjugate acid). 

Enzyme Reference Serums. Several companies sell lyophilized or stabilized reference serums for the calibration of instruments and for quality control. The label values given for the enzymatic activity of these serums should never be taken at face value, as at times they may be quite erroneous (19,33). Also, these values should only be used for the assay with which they were standardized, as interconversion of activity from one method to another for the same enzyme may often lead to marked errors. For instance, it is not recommended that alkaline phosphatase expressed in Bodansky units be multiplied by a factor to convert it to the units of the Ring-Armstrong method, or any other method for that matter. 

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